(adsbygoogle = window.adsbygoogle || []).push({}); I found this and thought I'd share this with you .
If you have anything you want to add just comment and I'll edit it. :mudkip:

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360: When the player spins 360 degrees
360-noscope: when the player spins a full 360 degrees and gets a kill with a sniper rifle from the hip.
360 Quick-scope: More difficult to pull off, involves a player spinning a full 360 degrees, quickly aiming down the scope, and scoring a one shot kill.

A
Ace: Killing the entire enemy Search & Destroy team all by yourself. Similar to Clutch. (See C.)
ADS: Aiming Down Sights.
AFK: Away From Keyboard.
Aimbot: A program used by a hacker to gain easy headshots etc. by automatically aiming the weapon without the player using the normal controls.
AR: Assault Rifle.

B
BEL: Behind Enemy Lines, a game mode in Call of Duty. (In CoD1 and Co United offense, I think) BG: bad game.
Boosting: The act of two or more players collaborating and killing each other repeatedly, usually to obtain kills/headshots/killstreaks without having to put in much effort, usually considered cheating by other players.
BRB: be right back.
Buff: An increase in the effectiveness of an item as the result of a patch.

C
Camp(-er, -ing): The act of staying in one specific area of a map while waiting for enemies to come into visual range.
Charlie: A contemporary slang term for the Viet Cong during the Vietnam War.
Choob: A skilled player that generally acts like a noob. (Never heard of that one)
Clutch: A situation in which a player (usually in Search and Destroy) is the last alive on their team. That player then proceeds to kill the 3, 4, 5, or 6 players left on the opposing team by themselves.
Co Call of Duty
CoD2: Call of Duty 2
CoD2:BRO: Call of Duty 2: Big Red One
CoD3: Call of Duty 3
CoD4:MW: Call of Duty 4: Modern Warfare
CoD5: Call of Duty: World at War
CoD6: Call of Duty: Modern Warfare 2
CoD7: Call of Duty: Black Ops
CoBO: Call of Duty: Black Ops
CoFH: Call of Duty: Finest Hour
CoMW2: Call of Duty: Modern Warfare 2
CoMW:R: Call of Duty: Modern Warfare: Reflex
CoRtV: Call of Duty: Roads to Victory
CoUO: Call of Duty: United Offensive
CoWaW: Call of Duty: World at War
CoWaW:FF: Call of Duty: World at War: Final Fronts
Collateral Damage (Collat): When a player gets two or more kills with one sniper bullet.
Cook: Holding a live grenade before throwing it; shortens the amount of time enemies have to react.
Commando Noob: A player who runs around knifing (usually with the tactical knife attachment) with a Marathon, Lightweight and Commando Class setup. (LOOL)
CTF: Capture the Flag.
Core: Non-hardcore modes.

D
Dedicated server: A server that is created solely to host multiplayer games.
DM: Deathmatch, a multiplayer game mode. Commonly referred to as a "Free For All" in the Call of Duty universe.
Dropshot: Going prone immediately upon encountering an enemy in close quarters combat in order to avoid gunfire while shooting.

E
Elevator Glitch (R.I.P ): A Glitch that causes the player to rise straight up into the air. Is considered a form of cheating by many.

F
Faggot Funnel: Another phrase for "noob tube". (LOOOL)
Flamewar/Flaming: The act of cussing or insulting another user/player with the hopes of starting an argument
Flanking: The act of circling around an enemy to attack them from the side or back
Flash: Flashbang
Floater : A term used to describe a player who jumps at the end of the match, to make him "Float".
FMJ: Full metal Jacket
FMJ Kill: A bullet penetration kill. See "Wall Bang".
F.N.G.: Acronym for "F*cking New Guy": Was originally a derogitory name used in the Vietnam war for new squad members sent from the U.S. to troops in Vietnam, as the veterans often found the new member lacking in essential jungle warfare skills.
Frag: Fragmentation grenade.
Friendly fire: Shooting an ally. This can cause failure in single player and is a setting that can be enabled in multiplayer.
FTL: For The Lose.
FTW: For The Win.
FU: F*ck You.

G
G18 Noob: a derogatory term towards a player who uses G18 Akimbo.
GG: good game.
GL: Short for Grenade Launcher.
Grenade spamming: Excessive usage of grenades/Semtex with little or no actual aiming. Usually in conjunction with the Scavenger or One Man Army perk.
Griefing: Intentionally ruining other players' fun by performing annoying actions (e.g. team-killing, using excessive flashbangs).
GTFO: Get the F*ck Out.

H
Hacker: Someone who hacks their disk or the game in order to alter the game.
Hardscope: The act of looking through the scope of a sniper and get a kill.
Headshot: Killing an enemy with a shot to the head. Often seen as a display of precision and skill.
Host: The player running a multiplayer game for other players to join. Applies to private matches and, more recently, Call of Duty: Modern Warfare 2's online play.
HQ: Headquarters.
HQ Pro: Headquarters Pro.
Holo: Holographic Sight.

I
IRC: Internet Relay Chat.
IRL: in real life.
Ivan: Russian Spetsnaz forces.
IW: Infinity Ward.

J
Jerry: A contemporary slang term for the Germans during World War II.
Juggernoob: Player that uses Juggernaut which is usually frowned upon.

K
K/D Whore: A player who tried his extreme hardest to get a good KD ratio every game, so his overall killdeath is very large.
K Another term for Kill:death ratio.
KDR: Kill:death ratio.
Killjack (Sometimes "Kill-Jack"): A less common term for "Killsteal".
Killsteal: The act of killing someone that someone else was already trying to kill, almost always accidental.
Knife fag: Derogatory term used against players who use only knifes (usually Tactical Knife) with Marathon, lightweight, and commando.
Kraut: Derogatory term for Germans during WWII.

L
LAG Switch: Cheat device designed to disrupt internet communication to the game server, causing all players in the match, aside from the user, to suffer high lag. Is considered a bannable offense by most game companies, and by LIVE and PSN.
LAG switcher: A player who attaches a lag switch to their internet in order to enable them to have an advantage over other players.
Leet (also written as l33t or 1337): Slang term for "elite", refers to a skilled and/or experienced player.
Leet speak: Form of internet slang that "leet" players use.
Level: Term used to refer to a mission. 2. Rank earned via XP in Multiplayer games in games such as MW2 and WaW
LMAO: Laugh(-ing) my ass off.
LMFAO: laugh(-ing) my ****ing ass off.
LMG: Light Machine Gun.
LOL: Laugh out loud.
LS: Short for Last Stand. Can also stand for "Luck Shot".
Luck Shot: To get a kill in a nearly impossible situation eg. killing an enemy by no-scoping at long range or getting an across map throwing knife kill.

M
Marty: Often used instead of Martyrdom in chat, like in : "No marty here."
Mod: Some form of game enhancing device what gives a player an advantage, oftentimes refers specifically to modded controllers.
Modded controller: A controller with a trigger that is modified to simulate rapid presses when held down, allowing the user to fire semi-automatic weapons as if they were fully automatic
MP40Juggernoob: A player who uses the MP40 in combination with Juggernaut.
MP: Map pack, A package of new maps available to download and play on so players can have a more fun with the gameMultiplayer: A gameplay mode that allows for multiple human players to play in the same game.
MVP: Most Valuable Player.
MW2: Call of Duty: Modern Warfare 2.

N
'Nade: Slang or short for grenade/Semtex.
NBK: Natural Born Killer.
Nerd Rage: Indignant, hysterical, and incoherent screaming brought on by video game induced frustration.
Nerf: A reduction in the effectiveness of an item as the result of a patch.
Noob: General: derogatory term used to express resentment toward another player, which used to mean "new player" but ended up as a cliche.
Noob tube: Derogatory term used to express resentment toward grenade launchers.
Noob Tuber: a derogatory term towards a player who uses grenade launchers excessively.
No Scoping: The act of firing the sniper rifle from the hip (i.e. without using the scope).
Nuke boosting: The act of killing an accomplice repeatedly to be able to call in a Tactical Nuke.

O
OMA: One Man Army
OMG: Oh my God
OMFG: Oh my f*cking God
One Shot Kill: killing an enemy with full health with a single sniper rifle bullet
Oscar Mike: Combination of the NATO phonetic alphabet words for O and M. when used in this combination, stands for "On the Move"
Own: to kill an enemy or enemies or win the match in a spectacular fashion.

P
Pwn: slang for "own" or to kill or beat in a flashy fashion
Pwnage: a flashy, amazing, or extraordinary kill or victory

Q
Quick Scoping: The act of scoping in, shooting, then scoping out almost instantly with a scoped sniper rifle. From a tactical perspective it does have the advantage of enabling quick one shot kills, but many players who use this tactic just end up sacrificing accuracy for style.

R
Ragequit: Ending or leaving a play session short because of anger toward the game or current situation. In Call of Duty games prior to Modern Warfare 2, the lack of host migration combined with ragequitting meant that many games were cut short by the host's departure.
RDS: Red Dot Sight.
Reload cancel: Cancelling a reload before the animation is completed to resume firing quicker.
ROFL: Rolling on the floor [laughing].
ROFLMAO: Rolling on the floor laughing my ass off.
ROFLMFAO: Rolling on the floor laughing my f*cking ass off.

S
S&: Search & Destroy, a multiplayer game mode.
Screenwatching: Watching another player's screen to know things about them that would otherwise be unknown, most notably that player's location. (also known as Screenhacking, Screencheating, and Screenpeeking).
Scrub: A player who uses the best of weapons, but can also do good with other weapons. Simply a more skillful form of a noob, but still in the category of noob.
Search: A common name for Search and Destroy.
SMG: Sub Machine Gun.
Smoke: Smoke grenade.
SP: Single Player.
S.S.D.D.: Same Sh*t Different Day.
Steam: Online distribution system and community. Keeps track of games played and friend list. Required to play the PC version of Call of Duty: Modern Warfare 2.
STFU: Shut the f*ck up.
Stun: Stun grenade.

T
Tactical Button Layout: Crouch and Melee buttons are switched. Common layout amongst people who Dropshot.
Tango Down: A phrase used for when an enemy has been killed
TDM: Team Deathmatch.
TDMEx: Team Deathmatch Express.
Tea-bag: When a player positions themself over top of a victim's body and repeatedly crouches and stands up as a of sign of humiliation. This supposedly simulates the action of placing one's scrotum on the other's face or mouth, mimicking the sexual act.
Team: Team Deathmatch.
TeamEx: Team Deathmatch Express.
Teamkill: Killing someone on the same team.
Thumper Dumper: Derogatory term for a player who excessively uses the Thumper, similar to the term "Noob Tuber".
Turtling: The act of putting a Riot Shield on your back and going prone.

U

V

W
Walking Bush: slang for a player whose character is wearing a Ghille Suit.
Wall Bang: The act of getting a bullet penetration kill.
WaW: Call of Duty: World at War.
Wonder Waffle: A slang term for the Wunderwaffe DG-2.

X

Y

Z

This is not my info. This is copied and pasted from another website and I edited and deleted some things. Some edited things are in RED and some things I just couldn't be botherd to show I'd edited.

Some of this I found pretty funny and I hadn't heard of some of these :p.

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This was totally useless...
1. you copy and pasted all of this
2. this is missing one of THE most important words
TANGO DOWN-ENEMY DOWN

im pretty sure i didnt see this in there.

1Bar, 2Bar, 3Bar, 4Bar - your connection in game.

"I'm on a 2Bar, this host is bad."

lol this is mostly basic stuff

AFC:Away from Controller

ftl= for the loss; not lose

another common one; BAMBI!= grenade/bomb :p