A nice glossary, new Fleet members who are new to MMOs can refer to this:
AoE: Area of effect. These are spells/buffs/etc that will only affect people, for good or bad within a specific range of the character.
Aggro: Short for aggrivation. Aggro is a point system that tells a monster which player it shoud attack, depending on how much damage or healing it can do.
Alt: An alternative character that's not played or favored as much. Alt-itus is used to describe a person who has many alts and plays them more than their main character.
CC: Crowd Control. Used to refer to any ability that hinders an opponent from attacking or moving.
DKP: Dragon Kill Points. A systemnormally used by raiding guilds in oder to distribute highly-sought after items fairly, based on how often a person plays.
DoT: Damage ove Time. DoTs come in the form of spells or poisons that deal a small amount of damage over a long period of time.
DPS: Damage Per Second. Damage dealing classes, such as those with high agility or powerful spells, generally have the greatest DPS.
E-Peen: Short for "electronic *****". Used to refer to someone's ego, especially when boasting, since big egos are needed to make up for small....things.
FPS: First Person Shooter. In this mode you can't see you character, but you can see your weapon and everything else around you.
Ganking: Literally, it means to steal something in game, it's a GANg Kill, eitherwhen one side has an unfair advantage due to numbers or a high level character kill a much lower one.
Greifing: When someone goes out of their way to ruin others play time.
HoT: Heal over Time. A heal that rejuvenates an ally slowly over time.
Kite: Used to describe the ation of dragging a mob behind a player. Generally a small amount of damage must be dealt every few seconds to keep the mob from de-aggroing.
KS(ing): Kill Stealing. This happens when one player attacks a creature someone else was attacking and they end up getting credit for the kill instead.
LoS: Line of Sight.
MA: Main Assist. They pull targets, tells which targets other players should be hiting, and sets the pace for the group.
Main: Your #1 character, as designed by the player. Generally there's a great deal of attachment to one' main, since they are normally a person's first character.
Mez: Short for mesmerize. An abiliy that takes control of an enemy's mind and either keeps it from moving around or controls it.
MDK: Murder Death Kill. To kill something completely and totally.
Mob: Originating from "mobile", mobs are monsters controlled by the game.
MT: Main Tank. The player who holds aggro while other players kill the enemies.
OT: Off Tanks. Hold aggro on other monsters when dealing with multiple enemies.
PK(er): A Player Killer.
PUG(s): Pick up group. A group made up of people who've never played with each other before. Generally less reliable than a guild.
PvE: Player versus Environment. Gameplay where a player fights mobs.
PvP: Player versus Player. Where players fight other players.
Raid: A large groupof people joined together to kill things.
RTS: Real Time Strategy. These are commonly single or multiplayer games and involve building defenses or moving trops.
Squishy: Used to describe a character who wears the weakest armor possible.
Wipe: Occurs when the entire group dies.
XP: Experience,which is a must for leveling up.