Roof - Area near the second cap at Badwater Basin
Map Room - the big room near RED spawn, overlooks the final cap at BadwaterBasin
Attic - beside C capture point, at Badwater Basin, there's a large building accessible by the stairs next to the point. If you go up those stairs and take a left, that's attic.
NS - Nice Shot
WTB - Willing to buy
S:, S>, S- Selling, with regards to an item they have
B:, B>, B- Buying, with regards to an item they want
Airshot - To shoot someone in the air. Usually refers to Grenades or Rockets.
Facestab - Wonky hit boxes, or excuses for a backstab registering when a spy stabs you from the front
DR Dead Ringer, a spy cloak watch that fakes death
Engineer/Engie Nest - A spot where an engineer has set up their sentry, dispenser and sometimes teleporter
Turtling - When an engineer stays between their dispenser and sentry and just hits their sentry with their wrench.
OP Overpowered
Solly Soldier
Spyro Spy disguised as Pyro
Spiral At Badwater Basin, the final cap has a spiral staircase on the left side near the RED spawn.
Vanilla Using stock weapons [the default]
W+M1 A pyro that holds down Left Mouse and walks forward. Typically an overexaggeration
Popped A medic used their ubercharge
Med Medic
Also some more obscure ones here:
http://wiki.teamfortress.com/wiki/Glossary_of_player_terms
