Symbols and Numbers

0 pop: (0 population) Leaving a player or village with no inhabitants.
1337: Elite
13x23: The extended view of the map available through plus.
15c/9c/6c: Land with 15, 9 and 6 cropper fields 
24/7: 24 hours 7 days a week
7x9: The view in the map while centered on a location.
+/+: North-East coordinates on the map.
+/-: South-East coordinates on the map.
-/+: Northwest coordinates on the map.
-/-: South-West coordinates on the map.

Versions

T2.5 (classic)
T3.5 (previous version)
T3.6 (previous version)
T4 (previous version)
T4.2 (previous version)
T4.4 (current version)

A

Aca: Academy
Afair: As far as I remember
Afaik: As Far as I know
Afk: Away From Keyboard. In Travian it means inactive.
Aggro: An alliance that attempts to kill all enemies, rather then build up a wonder
Aka: Also known as
Ally: Alliance
Analyser: one of the many Travian related sites that provides reports and details on changes in populations, growth, alliances etc. See here.
Anvil: A large defensive army, opposite of hammer
Artefact: A special item stored in the treasury that grants bonuses to its holder.
Asap: As soon as possible
Axes: Axeman

B

B2t/btt: back to topic
Ban (Forum): When a Moderator blocks access to your account for a rule violation. Rules are found here.
Ban (Game):When a MH locks your account for a rule violation. Message them at (0,0) to resolve this. Rules can be found here.
Bashing: Keeping a player small by attacking frequently
Battle Groups: A collection of players with in an alliance or meta that operate as a group for the purpose of coordinating attacks and/or defence.
Bonus: The bonus production of resources from oases.
Boonies: Located far from 0,0 - beyond the spawning locations
Bot: An illegal program that automates travian
BP: Beginners protection
Brb: Abbreviation for "be right back"
Btw: By the way
Bubble: Large number of defensive reinforcements in one village.
Bug: Error in the game. Please post all bugs here. 
Bump: A post that brings a thread back to the top.

C

.Com: The international servers of Travian, considered by many to be the most competitive
C: Abbreviation for "see"
Caesaris: Equites Caesaris
Capital: A special village that each player has only one of. Resource fields in this village can exceed level 10 and special building restrictions apply. A capital can never be conquered, but can be moved.
Cata: The act of catapulting (destroying buildings)
Catapults (catas/cats): Destroy buildings. Counts as infantry units.
Cheating: Violating the game rules.
Chief: Unit that captures other villages by reducing loyalty. Senator (Roman), Chief (Gauls), Chieftain (Teutons)
Chiefing: The act of using chiefs
Clear: Destroying the defending army before catapulting/conquering
Cleaner: Destroys the army, before a conquering
Clubbies: The first unit available to Teutons, the club swinger
Cluster: A number of villages close together, owned by the same player or alliance. Usually grouped together for protection.
CM: Community Manager
Confed: An alliance between two alliances
Construction Plans: An artefact that is required to build a World Wonder. A builder needs a set to build to 50, then needs another alliance member with a set to build past that.
Coords: Coordinates
Counter: A tactic in which a offensive army follows another one to its village.
CP: Culture Points, Confederate packs
Crop-locked: Village with a negative consumption due to the destruction of all pr most the crop(wheat) fields, grain mill and bakery. Can also be increased with the destruction of the market.
Crop: also known as wheat and grain, this is the resource that feeds your populace.
Cropper: a 9c or 15c
Cya: Abbreviation for "see you" or "goodbye"
Cyt: Abbreviation for "see you tomorrow"

D

Dc: Disconnect
Def: Defensive Troops
Deletion: A process in which an account is wiped from the travian map. Takes 72 hours.
Dmg: Damage from a unit
Double Target: When catapults may hit two targets. Requires a rally point level 20.
Druids: Druidrider
Dual: An account with multiple people running it
Dual Construction: An ability unique to the Romans that allows a resource field and a building in the village to be constructed simultaneously

E

EC: Equites Caesaris
EI: Equites Imperatoris
Elite: a single alliance with no wings and no alliances, opposite of meta
End Game: The period of the game after natar plan villages spawn. See the guide for the end game here.
End Game Hammer: A large hammer designed to secure plan villages or world wonder building sites
End Game Meta: A collection of alliances formed to support common world wonders
Epic: Something very awesome
Exp: Hero Experience
Expansion slot: The spots in a palace/residence where settlers/chiefs can be built.

F

Fake: Fake attack carried out by one or two troops, to confuse the target of the true attack force.
Farm: Player who is constantly raided for resources.
Farmer: A player who farms other players
Farming: The act of constantly attacking players for resources
Flame/Flaming: Being insulting on the forum.
Ftw: Abbreviation for "for the win"

G

GB: Great Barracks
GG: Great granary
Gl: Good Luck
Ghost Hammer: A large amount of Theuates Thunder used to quickly take down small pockets of defence.
GN: Good Night
Golding: Using gold for any purpose
GS: Great Stable
Gtg: Abbreviation for "got to go"
GTFO: Get the **** out, a rude way to say leave
Guide(s) A manual for a specific aspect of travian. Found here.
GW: great warehouse
Gz/Grz: Congratulations

H

Haeds: Haeduan
Hammer: Large offensive army used to clear and destroy villages
Hammer village: The village where a hammer is produced
HDT: Horse Drinking Trough
Hero: A special unit built at the heroes mansion that can grant bonus to other units and itself.
Hero's food: Easily killed units that give the hero experience
HM: Hero's Mansion

I

IGM: In Game Message
IGN: In Game Name
IIRC: If I remember correctly
Imo: In my opinion
Imp: Imperian
Insert: See Sniping
IRC: Internet Relay Chat

J

JK: Just Kidding

K

Kick: To remove someone from a channel or alliance

L

L8r: Abbreviation for "later"
Lag: Delay in page loading
Leg: Legionnaire
Lol/lawl: Abbreviation for "laugh out loud" or "lots of laughs"
Loot: Stolen resources
Lvl: Level

M

Macemen: See Clubbies
MB: Main Building
Merger: When multiple alliances decide to combine to form a Meta
Meta: A group of alliances with a central alliance and several large wings (see W: wings) with similar names all working together
MH: Multihunter
Mill: Grain Mill
Mirror Kill: See Second Kill
MM: Mass Message. A message sent out to every player in an alliance.
Mod: Moderator
MP: Marketplace
Multi: A player with multiple accounts. This is illegal.

N

NAP: Non-Aggression Pact, an agreement to refrain from attacking each other.
Necro'd: See Bump
Insert: The conventions of politeness on most forums/chat rooms
Newbie: A person who is new in Game or Forum.
Noob: A contemptuous (unfavourable) reference to a newbie. Many uses depending on context.
Np: No problem
NPC: Non Player Character
NPCing: Using NPC merchant to level out your resources

O

Oasis: Spot on the map with some sort of resource on it. Oasis are conquered by heroes and give production bonuses. Must have a hero mansion to conquer the oasis. The Oases 75%, 100%, etc.. are the total of a combination of oasis and almost exclusively refers to crop. 25/25 meaning crop and some other resource oasis bonus.
Off: Offensive Troop
Own: Owned- won against

P

PA: Plus Acount
Pala: Palace or Paladin (Teutonic Troop)
Pally: Abbreviation for "Paladin" (Teutonic troop)
Parking Village: Village that produces as much crop as possible to feed troops stationed there.
Phala: Phalanx
Plus: Plus Account
Pls/plz: Please
Pm: Abbreviation for "private message"
Pop: Population
Pushing: assisting another player against the rules, ie sending more than one hours resource per day to their village
Pusher: Player that practices pushing.
Pwn: Won against

Q

Quad: Quadrant, a players general location in game- NE, SE, SW, NW
Quad-line: The invisible line that separates the quadrants
Quests: An optional series of assignments meant to guide the beginner.

R

R: Abbreviation for "are"
Raid: An attack to gather resources from farms
Raider: A player who raids
Ram: A unit used to destroy walls, counts as infantry
Rammer: A ram hammer
Recruiter: Alliance member who helps find new members for an alliance
Reinforcements (Reins): Troops stationed in another village, usually for defensive purposes.
Res: Resource
Resi: Residence
Rice: See Crop
Rl: Real Life
Rofl: Rolling on the floor laughing- a way to say something is funny
Roflmao: Rolling on the floor laughing my *** off- a way to say something is funny
RP: Rally Point

S

Script: A program that overlaps with the original to give some modifications. Scripts are illegal.
Scouts: Pathfinders, ELs and Scouts
Scout hammer/anvil: A large number of scouts.
Second Kill: Timing your troops to land a second behind someone else's in an attempt to kill them.
Secondary Clear: A second clearing wave to eliminate any remaining defence.
Server: The location where a round of travian is taking place.
Sim City: Style of play where population is more important then troops. Generally considered a bad thing.
Simmer: A player who practices Sim City.
Sitter: The designated player who is sitting for someone.
Sitting: Controlling an account through the sitter function.
Skewer: Destroying an enemy offensive army at home.
Skype: A program used by travian players to communicate.
Smod: Super Moderator
Spam: A post that has nothing to do with the topic.
Spammer: A user who spams
Speed Server: A server that goes at 3x the speed of normal servers.
Spike: Placing defensive units in a village being farmed to hurt players that raid that village.
SPU: Same PC Usage
Spy (troop): Equites Legati (Roman), Scout (Teutons), Pathfinder (Gauls)
Spy (player): Someone in an alliance to gather information for other alliances
Split: See Sniping
Sniping: Inserting a defensive army between attacks to destroy catapults/senators.
Starvation: When there is no more wheat left and soldiers begin to die.
Supporters: Staff who answer questions sent to support.
Swords: Swordsman

T

TC: Treasure Chamber
TK: Teutonic Knight
TO: Trade Office
Torus: The 3D shape of the Travian map. (See below)
Tribute: Resources paid in to another player to stop attacks.
Troll: Someone who posts inflammatory statements in the forum for a reaction, don't feed the trolls!
TS: Tournament Square
TT: Theutates Thunder
Ttly: Talk to you later

U

U: Abbreviation for "you"
Ur: Abbreviation for "you're" or "your"
.us: The United States servers

V

Vassal: A player that gives tribute to another player for protection.

W

Wall: Earth Wall / City Wall / Palisade
Waves: Tactic that involves sending attacks followed with catapults.Waves should arrive at the same second in order to destroy or crop-lock a village.
Wb: Welcome Back
Wings: An alliance founded to work together with another alliance with the original alliance as leader
w00t: A phrase to express excitement
World Wonder Hammer: Very large offensive army used to knock down wonder villages. They usually have a crop usage in excess 250k / hour and more than 8k catapults or rams.
Wtf: What the F*ck
Wth: What the hell- a statement to express uncertainty
WW: World Wonder
WWK: World Wonder Killer- Very large offensive army used to knock down wonder villages.

X

-

Y

Y: Abbreviation for "why"

Z

Zerg Meta: A meta that focuses on gaining as many members as possible.
Zero: (0 population) Leaving a player or village with no inhabitants.