Terminology
GM Game Master
FS Full Support
Vag Vagrant
FM Force Master
Ment Mentalist
Arc Arcanist
CS   Crackshooter or Cash Shop  
Harle Harlequin
AoE Area Of Effect
Asal Asalraalaikum
SF Spirit Fortune
GT Geburah Tiphreth
HC Holycross
Merk Merkaba Hanzelrusha
HoP Hit of Penya
DI Dark Illusion
Ress Resurrection
HS Heavens Step
Grasp Priest's Grasp
EVA EVA Storm
Condor Condor Dive
ADV Advanced
Contrib Contribution Party
FD Lucky Drop
GB Gift Box
Link/LA Link Attack
Cove Crystal Cove
Queen Upresia 1/2
Kalgas Kalgas Cave
SM Saint Morning
D1/D2/D3 Darken 1/2/3
  VotR/Valley   Valley of the Risen
CoA Catacombs of Anguish
Azzy Azria
Trazzy Traseia
    
GS Guild Siege
GW Guild War
  BW/Blinks   Blink Wings
Pots Potions
QI Quest Items
Rema Remantis laccotte
IP Insanity Point
VP Vote Points
Amp Scroll of Amplification
Apro Scroll of AProtect
Gpro Scroll of GProtect
Spro Scroll of SProtect
Xpro Scroll of XProtect
RS Red Scroll
Revs Scroll of Reversion
Reduct A Scroll of Reduction A
Reduct B Scroll of Reduction B
CESS   Crystal Enchant Success Scroll  
CES Crystal Enchant Scroll
CTS Crystal Transformation Stone
UAS Unique Awake Scroll
CLC Conqueror Lord Cloak
MHT Monster Hunter Tokens
Say me /Say command
Exp Experience
KS Kill Steal
DC or D/C Disconnected
NPC Non-Player Character
PK Player Kill
Plvl Power Level
Leech Leeching
AFK Away From Keyboard
PM Private Message
PvP Player vs Player
PvE Player vs Enviroment
Awk Awakening

Credit to couples on the forums for putting this together! For a more in depth version visit the forums!