Add - Additional creature or group of creatures. Very bad news.

BoE - Bind on Equip, an Item that becomes soulbound to you once you equip it. Able to be sold at the AH if not used.

BoP - Bind on Pickup, an Item that becomes soulbound the moment you receive it. Can not be auctioned.

Buff – A beneficial spell or potion.

DKP - Dragon Kill Points. Earned by completing raid dungeons.

MT – Main Tank (Warrior who keeps primary mob's attention).

OT – Off Tank (Keeps a secondary mob out of the way).

Pull – Shoot or charge a single creature within a group causing them to attack.

Pat – Patrol (something's coming!).

Tank – Attack a creature and make sure the creature remains focused on you, typically a warrior talent.