Tasha, Suijin and Anon's have provided entries. If you'd like to provide some make a comment. Will update this post and put credit where its deserved.
++: Invulernable Save
d6: Roll 1 six sided dice
2d6: Roll 2 six sided dice
Alpha Strike: Tremendous amount shooting meant to cripple if greatly hinder the opponent in the first round of shooting.
AP: Armour Penetration. If weapons AP is less than Sv target cannot roll Save.
ATSKNF: and They Shall Know No Fear
BatRep: Battle Report. Results of a game.
BotBG: Blessing of the Blood God, Khorne Gift
Bubblewrap: Unit or units used to protect other units. q.v. 12.5.9 Necron vs Chaos Daemons for example.
CC: Close Combat
CD: Chaos Daemons
CSM: Chaos Space Marines
DBJ: Don't be a Jerk! Tag we put on back of CONvergence badges. Be cool, don't piss off fellow players thus maintain potential gamers for future games.
DE: Dark Eldar
DK: Dreadknight, Grey Knights
DoA: Descent of Angels. Ability of Blood Angels re-roll failed deep strike and scatter d6 instead of 2d6
DS: Deep Strike
DW: Draigowing, a Grey Knight army list
EML: Eldar Missile Launcher (p104 40k 5th)
(F)LGS: (Favourite[Friendly]) Local Gaming Store. The place where your wallet goes to die. [Friendly] Credit: Tasha.
FNP: Feel No Pain. Ability to shrug off some wounds. Chaos Space Marines Winds of Chaos not one of them.
GEQ: Guard Equivalent: Lots of 5+ or worse saves (low stats)
GK: Grey Knights
GKSS: Grey Knights Strike Squad
GT: Grand Tournament. Regional event that usually consists of 2-3 days of 40k battles to determine the best player at the event.
KP: Kill Points. One of three missions in the game.
LOS: Line of Sight
MEQ: Marine Equivalent: 3+ save (high stats)
MSU: Multiple Small Units. Elites, Troops, Fast Attack in squads less than 10. Designed to spam the field and provide target saturation. Target saturation provides a tremendous amount of units for your opponent to shoot at.
SoB = Sisters of Battle (AKA red-headed step children of the Imperium) Credit: Suijin.
Sv: Save, have to roll equal to or greater than number to avoid being wounded.
SW: Space Wolves
tic tacs: Little white tablets you use to win.
Tabled: Every model has been removed from the table.
TEQ: Terminator Equivalent: 2+ save (high stats)
TH/SS: Thunder Hammer/Storm Shield
VP: Victory Points. Victory Points equals the cost of the squad. i.e. Vect is killed opponent gets 240 VPs.
WAAC: Win at all Costs. A method to abuse the game mechanics to win the game.
WIP: Work in Progress, stages a model goes through when being put together and painted.