As a Smash researching community, it is our responsibility to define a rigid set of terms to unify smash language to make it more precise to discuss smash. For instance, if we were researching math, and I used the word "plus" and you used the word "obligation" for the same definition, we wouldn't get very far. This is an attempt to unify our speech to more quickly understand the game.
General/Tournaments
Super Smash Bros. 64/Melee/Brawl (SSB[64/M/B) {...}
Tourney {Tournament}
Advanced Technique (AT) {a technique Nintendo has not told us how to do}
Space Animals {Fox, Falco, Wolf; They're Animals... FROM SPACE}
John {Excuse; see: http://www.smashboards.com/showthread.php?t=79482 )
Mindgames {roughly: out-thinking your opponent. Don't use this term except in a joking/ sarcastic fashion.}
Sex Kick {Aerial with a long lasting hitbox and very little (if any) change in animation)
Metagame {The total sum of knowledge on a topic at it's highest level}
Lag {Time during an action where your character is vulnerable; i.e. startup/ cooldown of an attack}
Lag (network) {choppy connection that results in sub-par frame rates}
Lag (TV) {time it takes a TV to draw a signal. Has the same effects as Input Delay}
Bracket {Organizational structure of a tournament}
Single Elimination {Style of bracket where if you lose one set, you're eliminated from the bracket}
Double Elimination {Style of bracket where a player must lose two sets before being eliminated from the bracket; SBR Standard}
Pools {Section of a tourney for round robin play to eliminate people to make a smaller bracket; used to properly seed brackets[/b]
Game {a single normal round of smash}
Set (a.k.a. Match) {A best of # group of games; typically a best of 3 or best of 5}
Counterpick (CP) {Choosing the stage or your character for the next game in a set}
Smash Back Room (SBR) {group of the best players/ metagamers on Smashboards}
Out of State (OoS) {someone from a different state; Not to be confused with Out of Shield (OoS)}
Researching
Frame {A single iterative time step of the game. Melee and Brawl both run at 60 Frames per Second. Fundamental Timing unit of the game}
Frame # (#F) {A way to indicate that something occurs # Frames from the start of the frame breakdown - i.e. the beginning of the attack}
Frame Data {any breakdown describing when certain things happen in relation to other things using the Frame as the time unit}
Frame Advantage {Number of frames someone who attacks someone else's shield is able to act before the shielder}
Autocancel #1 #2 {the attack autocancels if the character lands before #1 frames of the move has finished, or after #2 frames of the move have finished}
Melee And Brawl
Turn Around Neutral B (Reverse Neutral B) {in the air, tap back, then neutral B; turns your neutral b around}
Boost Grab {interrupting the initial frames of a dash attack with a grab; can be used for extra momentum}
Dash {the initial section of a run}
Fox Trotting {Starting a new dash at the end of your dash window}
Jump Cancel (JC) usmash/Up-B {During the jump startup, usmash or up b; does a grounded usmash/up b}
Pivot Grab {melee: pivot into a grab; brawl: hit back then grab: performs a special reverse grab}
Auto Cancel {landing while during a specific window on an attack resulting in only normal landing lag}
Meteor Cancel {canceling momentum of a Meteor Smash}
Shield Canceling {shield to stop running}
De-sync [ICs] {having the ICs do separate things or with separate timings}
Rising Pound [jiggs] {Jiggs' upward angled side b}
Missile Canceling [Samus]{landing right after shooting a missle with samus}
Short Hop (SH) {releasing the jump command before leaving the ground; shorter jump}
FastFall (FF) {pressing down on the way down while in normal aerial control; fall faster}
Shield Grabbing {grabbing out of shield}
Teching {pressing R before being slammed into a surface; cuts knockback/ stands up fast}
Edge Hogging {being on the edge preventing someone else from being on it}
Edge Hopping (aka Ledge Hopping){dropping from the edge, then air jumping back to the stage}
Edge Jumping (aka Ledge Jumping) {Jumping off of the edge by pressing a Jump input while on the edge}
Dash Dancing {dashing one way, then the other during dash}
Hitlag {The freeze frames shared by the hitter and hittee of an attack after hit, but before the hittee is sent flying}
Hitstun {The window which someone sent flying can take no actions in}
Directional Influence (DI) {Bending the trajectory of knockback by holding the control stick in a perpendicular to knockback position during the last frame of hitlag; "DI" ONLY applies to the bending of knockback while being hit, not while moving your character through the air}
Smash DI (SDI) {Pressing the control stick during hitlag to give you an instantaneous small teleport}
Automatic Smash DI (ASDI) {Holding a direction during the last frame of hitlag with either stick - c stick has priority - to generate a teleport 1/2 SDI length in the direction held}
Drifting {Holding sideways in the air while under control of your character to cause it to move more left or right; NOT DI}
Tumble {The window which someone sent flying can take an action in, but is still falling}
Blockstun {The window which a shielder is stuck in shield after the shield is hit NOT COUNTING HITLAG}
Powershield {Shielding only a few frames before an attack would hit you and getting the different shield}
Short Hop (optional]Double/ triple) Laser (SH[D/T]L) [Fox, Falco, Wolf]
Float Cancel [Peach]{dropping out of a float to the ground to end an aerial; normal landing lag in Melee}
Needle Canceling [Sheik] {pressing R to cancel charging needles on sheik}
Shield Dropping {on a platform out of your shield, slowly press down to drop through the platform, from directly in your shield}
Jump Cancel _____ (JC _____) {canceling your jump with ______}
Jump Canceling (no abbrv) {canceling something with a jump}
Bomb Jump [samus] {receiving a vertical boost from a down b exploasion (samus only)}
Zair {an aerial done using the grab button that is not a nair, fair, dair, bair, or uair}
Tether Recovery [anyone with a zair] {brawl: autosweetspots the edge - fails if edgehogged; Melee can grab the wall anywhere and doesn't afraid of anything}
Walljump [several characters] {Jumping off a wall; does not take a midair jump}
Sweetspot {grabbing the edge directly out of your recovery, removing the ending animation; alternatively, grabbing the edge from max range; when referencing a part of an attack, the hitbox that has the most effect}
Grab Release {when a grabee breaks out of a grab}
Chain Grab (CG) {Grabbing a character just thrown before their hitstun ends}
Out of Shield (OoS) {performing an action from in your shield}
Brawl
Platform Auto Snap {Pressing down when passing through a moving platform to automatically land on it}
B-Reversal {smash back immediately after doing a special; turns you around in some specials}
B Bouncing (BB) {using momentum from a momentum generating special to push you}
Boost [Smashing/Item Throwing/Pivot Grab] (replaces the term DAC/ DACUS){Immediately canceling a dash attack by either a usmash, throwing an item, or pivot grabbing; slides various distances}
Craq Walking {Drifting backwards and taking a single step backwards when landing to gain a momentum slide}
Glide Toss {throwing an item in the early part of a roll; ends the roll with momentum}
Jump Cancel (JC) Item Throw {canceling a jump with an item throw; generates momentum}
Platform Drop Cancel {begin dropping through a platform put up your shield; end in standing shield position on the platform}
Reverse Aerial Rush (RAR) {run, turn around, jump; in the air facing opposite how you were running, with momentum in the direction of your run}
Edge Popping {holding down to avoid sweetspot}
Grab Armor (Armor Grab) {The superarmor received while you are grabbing, on the frame you grabbed them}
AirWalk {run off the edge, and walk back onto it}
Crawl Dashing {walk forward, start crawling back; slide backwards}
Jab Lock {locking someone in a fallen state with jabs}
Stutter Stepping {using the window for pressing sideways for an fsmash to dash a bit then fsmash}
Dribbling {glide tossing downward to generate different movement}
Infinite Second Jump (ISJ) ?better term? {performing a double jump right before landing with certain aerials or specials; instead of landing, you double jump, refreshes double jump}
Dashing Usmash {doing a usmash directly out of dash}
Dash Attack Hit Cancel Up Smash (DAHCUS) {cancels a dash attack immediately into a usmash after hit; only in early part of dash attack}
Edge Hugging (Hugging) {running off the edge, and immediately grabbing it by holding back}
Instant Pivot Grab {inputting dashgrabcstick back; performs a pivot grab very quickly}
Dashing Usmash {pressing up C to perform a usmash out of run/dash}
Input Delay {Built in time it takes your input to take effect when playing on Wifi}
Melee
Jump Cancel Grab (JC grab) {canceling the startup of a jump into a standing grab}
L cancel {pressing L/R/Z within 6 frames of landing with an aerial to cut landing lag in half}
SHFFL {Short Hop aerial Fast Fall L cancel}
Wavelanding {air dodging into the ground to generate a momentum slide}
Wavedashing {wavelanding immediately after leaving the ground}
Waveshining {wavedashing out of a shine}
Waveshield {wavedashing out of a shield}
Dash Canceling {pressing down to cancel a dash into a crouch}
Pivot {making use of the single standing frame during the turnaround of a dash dance}
Crouch Canceling {crouching when being hit to reduce knockback, hitstun, and launch angle}
Pillaring {shield pressure technique of multiple iterations of an aerial into a shine}
Moon Walking {input back at the start of a dash w/o centering the control stick to generate backwards momentum}
Double Jump Cancel (DJC) {canceling your second jump with an aerial; select characters only}
Depreciated
SHAD (Short Hop Air Dodge) - this doesn't need to be a term and is no way resembling an AT
Shellshifting {squirtle running turn around}
Dash Pivot Cancel {IASA turn around lag; slide w/ an attack opposite your movement}
Snakedashing {using snake's Boost Usmash}
DACUS (no dash attack hit) {replaced by "Boost Usmash"}
DLX Hit Cancel {replaced by DAHCUS}
Hyphen Smash {replaced by "Dashing Usmash"}
General/Tournaments
Super Smash Bros. 64/Melee/Brawl (SSB[64/M/B) {...}
Tourney {Tournament}
Advanced Technique (AT) {a technique Nintendo has not told us how to do}
Space Animals {Fox, Falco, Wolf; They're Animals... FROM SPACE}
John {Excuse; see: http://www.smashboards.com/showthread.php?t=79482 )
Mindgames {roughly: out-thinking your opponent. Don't use this term except in a joking/ sarcastic fashion.}
Sex Kick {Aerial with a long lasting hitbox and very little (if any) change in animation)
Metagame {The total sum of knowledge on a topic at it's highest level}
Lag {Time during an action where your character is vulnerable; i.e. startup/ cooldown of an attack}
Lag (network) {choppy connection that results in sub-par frame rates}
Lag (TV) {time it takes a TV to draw a signal. Has the same effects as Input Delay}
Bracket {Organizational structure of a tournament}
Single Elimination {Style of bracket where if you lose one set, you're eliminated from the bracket}
Double Elimination {Style of bracket where a player must lose two sets before being eliminated from the bracket; SBR Standard}
Pools {Section of a tourney for round robin play to eliminate people to make a smaller bracket; used to properly seed brackets[/b]
Game {a single normal round of smash}
Set (a.k.a. Match) {A best of # group of games; typically a best of 3 or best of 5}
Counterpick (CP) {Choosing the stage or your character for the next game in a set}
Smash Back Room (SBR) {group of the best players/ metagamers on Smashboards}
Out of State (OoS) {someone from a different state; Not to be confused with Out of Shield (OoS)}
Researching
Frame {A single iterative time step of the game. Melee and Brawl both run at 60 Frames per Second. Fundamental Timing unit of the game}
Frame # (#F) {A way to indicate that something occurs # Frames from the start of the frame breakdown - i.e. the beginning of the attack}
Frame Data {any breakdown describing when certain things happen in relation to other things using the Frame as the time unit}
Frame Advantage {Number of frames someone who attacks someone else's shield is able to act before the shielder}
Autocancel #1 #2 {the attack autocancels if the character lands before #1 frames of the move has finished, or after #2 frames of the move have finished}
Melee And Brawl
Turn Around Neutral B (Reverse Neutral B) {in the air, tap back, then neutral B; turns your neutral b around}
Boost Grab {interrupting the initial frames of a dash attack with a grab; can be used for extra momentum}
Dash {the initial section of a run}
Fox Trotting {Starting a new dash at the end of your dash window}
Jump Cancel (JC) usmash/Up-B {During the jump startup, usmash or up b; does a grounded usmash/up b}
Pivot Grab {melee: pivot into a grab; brawl: hit back then grab: performs a special reverse grab}
Auto Cancel {landing while during a specific window on an attack resulting in only normal landing lag}
Meteor Cancel {canceling momentum of a Meteor Smash}
Shield Canceling {shield to stop running}
De-sync [ICs] {having the ICs do separate things or with separate timings}
Rising Pound [jiggs] {Jiggs' upward angled side b}
Missile Canceling [Samus]{landing right after shooting a missle with samus}
Short Hop (SH) {releasing the jump command before leaving the ground; shorter jump}
FastFall (FF) {pressing down on the way down while in normal aerial control; fall faster}
Shield Grabbing {grabbing out of shield}
Teching {pressing R before being slammed into a surface; cuts knockback/ stands up fast}
Edge Hogging {being on the edge preventing someone else from being on it}
Edge Hopping (aka Ledge Hopping){dropping from the edge, then air jumping back to the stage}
Edge Jumping (aka Ledge Jumping) {Jumping off of the edge by pressing a Jump input while on the edge}
Dash Dancing {dashing one way, then the other during dash}
Hitlag {The freeze frames shared by the hitter and hittee of an attack after hit, but before the hittee is sent flying}
Hitstun {The window which someone sent flying can take no actions in}
Directional Influence (DI) {Bending the trajectory of knockback by holding the control stick in a perpendicular to knockback position during the last frame of hitlag; "DI" ONLY applies to the bending of knockback while being hit, not while moving your character through the air}
Smash DI (SDI) {Pressing the control stick during hitlag to give you an instantaneous small teleport}
Automatic Smash DI (ASDI) {Holding a direction during the last frame of hitlag with either stick - c stick has priority - to generate a teleport 1/2 SDI length in the direction held}
Drifting {Holding sideways in the air while under control of your character to cause it to move more left or right; NOT DI}
Tumble {The window which someone sent flying can take an action in, but is still falling}
Blockstun {The window which a shielder is stuck in shield after the shield is hit NOT COUNTING HITLAG}
Powershield {Shielding only a few frames before an attack would hit you and getting the different shield}
Short Hop (optional]Double/ triple) Laser (SH[D/T]L) [Fox, Falco, Wolf]
Float Cancel [Peach]{dropping out of a float to the ground to end an aerial; normal landing lag in Melee}
Needle Canceling [Sheik] {pressing R to cancel charging needles on sheik}
Shield Dropping {on a platform out of your shield, slowly press down to drop through the platform, from directly in your shield}
Jump Cancel _____ (JC _____) {canceling your jump with ______}
Jump Canceling (no abbrv) {canceling something with a jump}
Bomb Jump [samus] {receiving a vertical boost from a down b exploasion (samus only)}
Zair {an aerial done using the grab button that is not a nair, fair, dair, bair, or uair}
Tether Recovery [anyone with a zair] {brawl: autosweetspots the edge - fails if edgehogged; Melee can grab the wall anywhere and doesn't afraid of anything}
Walljump [several characters] {Jumping off a wall; does not take a midair jump}
Sweetspot {grabbing the edge directly out of your recovery, removing the ending animation; alternatively, grabbing the edge from max range; when referencing a part of an attack, the hitbox that has the most effect}
Grab Release {when a grabee breaks out of a grab}
Chain Grab (CG) {Grabbing a character just thrown before their hitstun ends}
Out of Shield (OoS) {performing an action from in your shield}
Brawl
Platform Auto Snap {Pressing down when passing through a moving platform to automatically land on it}
B-Reversal {smash back immediately after doing a special; turns you around in some specials}
B Bouncing (BB) {using momentum from a momentum generating special to push you}
Boost [Smashing/Item Throwing/Pivot Grab] (replaces the term DAC/ DACUS){Immediately canceling a dash attack by either a usmash, throwing an item, or pivot grabbing; slides various distances}
Craq Walking {Drifting backwards and taking a single step backwards when landing to gain a momentum slide}
Glide Toss {throwing an item in the early part of a roll; ends the roll with momentum}
Jump Cancel (JC) Item Throw {canceling a jump with an item throw; generates momentum}
Platform Drop Cancel {begin dropping through a platform put up your shield; end in standing shield position on the platform}
Reverse Aerial Rush (RAR) {run, turn around, jump; in the air facing opposite how you were running, with momentum in the direction of your run}
Edge Popping {holding down to avoid sweetspot}
Grab Armor (Armor Grab) {The superarmor received while you are grabbing, on the frame you grabbed them}
AirWalk {run off the edge, and walk back onto it}
Crawl Dashing {walk forward, start crawling back; slide backwards}
Jab Lock {locking someone in a fallen state with jabs}
Stutter Stepping {using the window for pressing sideways for an fsmash to dash a bit then fsmash}
Dribbling {glide tossing downward to generate different movement}
Infinite Second Jump (ISJ) ?better term? {performing a double jump right before landing with certain aerials or specials; instead of landing, you double jump, refreshes double jump}
Dashing Usmash {doing a usmash directly out of dash}
Dash Attack Hit Cancel Up Smash (DAHCUS) {cancels a dash attack immediately into a usmash after hit; only in early part of dash attack}
Edge Hugging (Hugging) {running off the edge, and immediately grabbing it by holding back}
Instant Pivot Grab {inputting dashgrabcstick back; performs a pivot grab very quickly}
Dashing Usmash {pressing up C to perform a usmash out of run/dash}
Input Delay {Built in time it takes your input to take effect when playing on Wifi}
Melee
Jump Cancel Grab (JC grab) {canceling the startup of a jump into a standing grab}
L cancel {pressing L/R/Z within 6 frames of landing with an aerial to cut landing lag in half}
SHFFL {Short Hop aerial Fast Fall L cancel}
Wavelanding {air dodging into the ground to generate a momentum slide}
Wavedashing {wavelanding immediately after leaving the ground}
Waveshining {wavedashing out of a shine}
Waveshield {wavedashing out of a shield}
Dash Canceling {pressing down to cancel a dash into a crouch}
Pivot {making use of the single standing frame during the turnaround of a dash dance}
Crouch Canceling {crouching when being hit to reduce knockback, hitstun, and launch angle}
Pillaring {shield pressure technique of multiple iterations of an aerial into a shine}
Moon Walking {input back at the start of a dash w/o centering the control stick to generate backwards momentum}
Double Jump Cancel (DJC) {canceling your second jump with an aerial; select characters only}
Depreciated
SHAD (Short Hop Air Dodge) - this doesn't need to be a term and is no way resembling an AT
Shellshifting {squirtle running turn around}
Dash Pivot Cancel {IASA turn around lag; slide w/ an attack opposite your movement}
Snakedashing {using snake's Boost Usmash}
DACUS (no dash attack hit) {replaced by "Boost Usmash"}
DLX Hit Cancel {replaced by DAHCUS}
Hyphen Smash {replaced by "Dashing Usmash"}