Someone in another thread asked if something like this existed already and since it doesn't seem to I'll have a go at making one myself.
General Terms
PvE - Player versus Environment - PvE is what makes up the majority of TERA's Content and refers to anything where the player is up against non player controlled enemies.
PvP - Player versus Player - PvP refers to combat between two or more players.
RP - Roleplaying - Roleplaying is when players act as though they were a character within a game as opposed to merely someone playing it.
Guild - A Guild is a group of players who usually work together towards a shared goal, these goals can be anything from PvE advancement or winning lots of PvP battles to just having a fun community to hang out with.
GvG - Guild vs Guild - a PvP activity where two guilds declare war on one another and score points for killing members of the enemy guild.
GM - Guild master - A Guild master is the leader of a Guild
Main - Main Character - Used to refer to the character you spend most of your time playing.
Alt - Alternative Character - Refers to non main characters.
LFG - Looking for group - exactly what it says on the tin whoever is using it is looking for a group for something.
LFM - Looking for more - Like lfg except the person already has part of a group and just needs another person or two to fill it.
IM - Instance Matcher - a tool used to find groups for instances. Queuing for instances via the IM gives various perks such as reduced cooldowns on dungeons entered with it, as such you'll occasionally see people asking for people to queue instead of joining their group directly.
POI - Point of Interest -Used to link a map location in chat. Anyone who clicks on it will have the targeted location marked on their map. Can be linked by holding the left control key and left clicking anywhere on your map or minimap.
Tank - A class which is designed to distract enemy attention away from other party members. (Lancer and Warrior).
Healer - Classes designed to heal damage inflicted on allies. (Mystic and Priest).
DD - Damage dealer - Classes designed to inflict large amounts of damage on enemies. (Berserker, Slayer, Sorcerer, Archer, Warrior).
DPS - Damage Per Second - Used to refer to a player's average damage inflicted over a period of time. Also occasionally used by players looking for damage dealing party members.
CC - Crowd Control - Spells and abilities which are used to make enemies more manageable. For example, putting one of of a pair of enemies to sleep or slowing a group of enemies.
Bank - Stores your items for you! Banked items will be available from any banker in the world (all towns have banks). Banked items are also shared between all your characters on that server.
Mailbox - Used to send messages and parcels to other players. Can be accessed via the bank.
C.O.D - Charge On Delivery - Allows you to set a charge that the recipient of a message or parcel must pay in order to open it. Unfortunately the postage of COD items is too high for it to be much use.
GB - Guild bank - Like a regular bank except it's shared between and only accessible by members of a guild. Guild masters can restrict bank access to certain ranks.
TB -Trade Broker - Used to trade items with others on the server without the hassle of tracking them down and trading directly.
BO - Buyout - The trade broker offers the option to either negotiate a price with the seller or buy it straight away without negotiation, selecting buy now adds a percentile fee to the cost of the purchase. This term isn't used much but does come up occasionally.
Glyph - A glyph is a type of character customisation which becomes available around level 20. Glyphs can be learned for various skills and add additional effects to their respective skills.
Glyph Points - Used to activate learned glyphs, all of which have a points cost required to activate them. Characters get 10 glyph points at level 20 and then one point per level after that for a total of 50 points at level 60.
Remodeling - Remodeling allows you to change the appearance of your equipment to that of another piece of equipment. Yay character customization! You can only remodel items using those of the same type (IE you can't remodel an axe into a greatsword or a robe into a chestplate).
Template - A template is the item that items being remodeled take the appearance of. Most weapons and armour are eligable as templates. The template is lost in the remodeling process though.
BAM - Big Ass Monsters - BAMs are basicly large monsters designed to be fought in a group (a lot of them can be soloed with a bit of effort and practice though). Most areas have them and the majority of dungeon bosses are also BAMs
AoE - Area of Effect - This refers to any ability that hits an area as opposed to a single target.
DoT - Damage over Time - Effects which cause periodic damage at set time intervals (such as poison) are refered to as DoTs .
HoT - Heal over Time - Like DoTs but much nicer (unless it's on the enemy of course).
Proc - A Proc is an additional effect which has a chance to trigger under certain conditions, for example certain glyphs can provide a small chance to reset a skill's cooldown on use.
Soulbound - A Soulbound item is an item which is bound to a certain character and cannot be traded to or equiped by any other characters. Soulbound items can still be destroyed or sold to a merchant.
BoE - Bind on Equip - Refers to items which become soulbound to your character when equipped. Most items which drop are BoE.
BoP - Bind on Pickup - BoP items will become soulbound to your character as soon as you loot them and thus can never be traded.
GS/ TS - Greatsword and Twinswords - Occasionally used to refer to the Slayer and Warrior classes' weaponry.
Tier - All weapons and armour (aside from a few low level ones) have a tier. The tier is a general indication of the power of an item with each tier being better than the previous. There are currently 14 tiers of equipment, T1 is the lowest and T14 is the highest.
VM - Visionmaker - The best equipment currently available. Has to be crafted with various difficult to get materials.
Vitriol - Argon Vitriol. Rare crafting material used to craft Visionmaker equipment
Quills - Shandra Quills - Crafting material dropped by the final boss in MCHM (see dungeons section). Used to craft Visionmaker equipment
Adds - Additional enemies - Used to refer to extra monsters summoned by or accompanying a boss monster
BG - Battleground - Refers to the Fraywind Canyon PvP instance which becomes available at level 60
Praise - Praising a guild helps them become more recognized and if they're a Vanarch guild will give them a small amount of PP
Alka - Alkahest - Powder used in enchanting, comes in four types used for various levels of enchantment.
Fodder - Fodder refers to the item which is sacrificed in order to make an enchanting attempt.
Enigmatic - An Enigmatic item has its' effects hidden and cannot be equipped until identified.
Each time an enigma is removed the effects are randomized so deliberately making items enigmatic can be used to reroll effects.
MW - Masterwork - Masterwork equipment can be enchanted past the usual limit of +9 to +12 using Masterwork alkahest.
MES/ Scrolls - Master Enigmatic scrolls - Used to attempt to masterwork items.
Rep - Reputation - Starting at level 59 you can improve your reputation with various factions in order to gain access to various rewards. Also occasionally used to refer to reputation credits which are used to purchase some of said rewards.
Agni - Agnitor - The Reputation faction associated with the Nexus (see below).
Dungeons and Raids
NM / HM - Normal mode and Hard mode - Some high level instances have an optional hard mode which is more difficult but gives better rewards.
Nexus - Nexus is a world event which takes place 1-2 times a day throughout the week. Nexuses open in several locations in high level zones and players have to close them, doing so provides them with gold and Agnitor reputation as well as access to the Nexus Traverse (see NT below). Nexuses can be participated in from level 59.
BoL - Bastion of Lok - The first instanced 5 person dungeon in the game, available at level 20.
SM - Sinestral Manor - The second dungeon (level 26).
CR - Cultist's Refuge - The third dungeon (level 35).
NT - Necromancer Tomb or Nexus Traverse - The fourth dungeon (level 41). Alternatively NT can refer to Nexus traverse, a raid instance which serves as the second part of the Nexus
SA - Sigil Adstrango - A challenging optional dungeon (has no story quests). available from level 45.
GL - Golden Labyrinth - The sixth dungeon (level 48).
AH - Akasha's Hideout - The seventh dungeon (intended to be run after GL since it requires an item from there) (level 48, has a hard mode).
AoS - Ascent of Saravash - Another optional dungeon (level 52).
SSG - Saleron's Sky Garden - The ninth dungeon (level 53).
SP - Suryati's Peak - Another optional dungeon (level 56).
LoT - Labyrinth of Terror - The eleventh dungeon (level 58, has a hard mode at level 60).
ET - Ebon Tower - The twelfth dungeon (level 58, has a hard mode at level 60).
KN - Kelsaik's Nest - Thirteenth dungeon (level 58, has a hard mode at level 60).
FoK - Fane of Kaprima - Level 60 dungeon. Considered obsolete by a lot of people due to newer content. Has Hardmode
BT - Balder's Temple - Level 60 dungeon. Also considered obsolete. Has Hard mode
ToT - Temple of Temerity - Level 60 dungeon. Awards badges used to purchase advanced glyphs
SG - Sirjuka Gallery - level 60 dungeon. Awards talents used to purchase advanced glyphs
AC - Argon Corpus - level 60 dungeon. Has Hard mode
MC - Manaya's Core - Level 60 dungeon and currently the hardest instance in the game. Has Hard mode
CoF - Crucible of Flame - recently added level 60 dungeon.
The Political System
Vanarch - The Vanarch is the ruler of a province, Vanarchs are decided either via a vote held once per month or via GvG combat depending on the province.
Catharnach awards - Catharnach awards are required in order to level up a guild and register to run for Vanarchy.
PP - Policy Points - Policy points are used by Vanarchs to keep shops and skill trainers open within their controlled province. Policy points are gained either by completing special Vanarch guild only quests or via praise.
That's everything I can think of for now. If you know of any terms, acronyms or alternative definitions which you think should be included please tell me so I can add them.
