(Yes, I know this forum has the mouseover glossary, personally I found it more annoying than helpful, plus I like to have everything in one place. And as you can see, it's incomplete :v)
 
 "So he revealed a TO HI from HD in ARO and now ML shots are flying around, what am I supposed to do and more importantly, what the 
 is he talking about!? 
 "
 
 If you're new to Infinity, you might have already noticed we use a lot of acronyms to save time. This list written to facilitate the introduction, so you may soon sling TLAs with the best of them. If I missed anything, let me know!
 
 
(To experienced players: Yes, the descriptions are superficial and incomplete. This is an intro glossary, not a wiki.)
 
 
 
 360V = 360ยบ Visor
 
AD = Airborne Deployment
 
AD1 = Airborne Deployment: Parachutist (choose a table edge quarter before the battle)
 
AD2 = Airborne Deployment: Airborne Infiltration (choose the table edge quarter immediately before landing)
 
AD3 = Airborne Deployment: Combat Jump (place a circular template and land in that area)
 
ADHL = Adhesive Launcher
 
AP = Assault Pistol / Armor-Piercing [ammo] / Anti-Personnel [mines]
 
ARO = Automatic Reaction Order (pretty much everything you do in the reactive turn)
 
ASA = Acontecimento Shock Army (a PanOceanian sectorial army)
 ASS = Assault Sub-Section of the ALEPH forces (a.k.a. Steel Phalanx sectorial)
 B = Burst
 
B2B = Base-to-base contact
 BJC = Bakunin Jurisdictional Command (Nomad sectorial)
 
BS = Boarding Shotgun / Ballistic Skill
 
BSG = Boarding Shotgun
 
BTB -> 
B2B
 CA = Combined Army
 
CB = Corvus Belli
 
CC = Close Combat (statistic ("CC roll"

 or situation ("we're in 
CC"

)
 
CCW = Close Combat Weapon
 
CG = Celestial Guard (a Yu Jing unit)
 
CH = Camouflage and Hiding (the whole skill tree)
 
CHA = Caledonian Highlander Army (an Ariadnan sectorial army)
 Cheerleader = model whose main purpose is to provide a regular order to others
 CJC = Corregidor Jurisdictional Command (Nomad sectorial)
 
CP = Campaign: Paradiso (the third Infinity book)
 CRAP = Chain Rifle, Assault Pistol (a S.A.S. unit loadout)
 DEP = Descanse en Paz ("Rest in Peace" - a one-shot anti-armor launcher)
 DTW = Direct Template Weapon (anything that uses a template and auto-hits; mostly chain* and flamers)
 
EI = Evolved Intelligence (the entity that runs the 
CA)
 EVO = EVO Repeater
 GdA = Guarda 
de Asalto (a PanOceanian unit)
 GHRL = Guided Heavy Rocket Launcher (incendiary weapon)
 
GML = Guided Missile Launcher (anti-armor weapon)
 GMSR = Guided Multi Sniper Rifle
 F2F = Face-to-Face roll
 
FO = Forward Observer
 FRRM -> MRRF
 
FTF = Face-to-Face roll
 
HB = Hassassin Bahram (Haqqislam sectorial)
 
HD = Hacking Device / Hidden deployment (when a unit starts hidden with not even a marker, only a position on the map noted down)
 
HD+ = Hacking Device Plus
 HFT = Heavy Flamethrower
 
HGL = Heavy Grenade Launcher
 
HI = Heavy Infantry (i.e. powered armor)
 
HMC = Hyper-Rapid Magnetic Cannon, =HRMC
 
HMG = Heavy Machine Gun
 Holo1 = Holoprojector Level 1 (appear as another unit)
 Holo2 = Holoprojector Level 2 (fake holoechoes)
 HRL = Heavy Rocket Launcher (incendiary weapon)
 HRMC = Hyper-Rapid Magnetic Cannon, =
HMC
 HS = Human Sphere (the second Infinity book)
 
ICS = Infinity Campaign System
 IMP = Impersonation or Impersonation Marker
 
ISS = IS = Imperial Service (sometimes unofficially called the Imperial Secret Service; a Yu Jing sectorial army)
 ITS = Infinity Tournament System
 
JSA = Japanese Sectorial Army
 KSCD = Kuang Shi Control Device (often mentioned because this loadout also has a Smoke 
LGL)
 KTS = Kaplan Tactical Services (a mercenary unit/organization)
 LFT = Light Flamethrower
 
LGL = Light Grenade Launcher
 
LI = Light Infantry
 
LoL = Loss of Lieutenant
 
LRL = Light Rocket Launcher (incendiary weapon)
 LSG = Light Shotgun
 LSGL = Light Smoke Grenade Launcher
 LT = Lieutenant (an army commander)
 
MA# = Martial Arts level #
 
MAF = Morat Aggression Force (a Combined Army sectorial)
 MAS = Micro Art Studio (company that makes "official" Infinity terrain)
 
MI = Medium Infantry
 Mk12 = Mk12 (A battle rifle. Yes, it's its full name)
 
ML = Missile Launcher (anti-armor weapon)
 
MO = Military Orders (a PanOceanian sectorial army)
 
MR = Multi Rifle
 MRRF = Merovingian Rapid Response Force (an Ariadnan sectorial army, a.k.a. FRRM from the French variant)
 
MSR = Multi Sniper Rifle (multiple ammunition types, not multiple snipers 

 )
 
MSV# = Multi-Spectral Visor level #
 NCA = Neoterran Capitalline Army (PanO sectorial)
 
NWI = Valor: No Wound Incapacitation (unit can be fully active when "unconscious"
 ODD = Optical Disruption Device (no full camouflage, but -6 to hit)
 ODF = Optical Disruption Field (Pi-Well has it, gives 
ODD to all models within a circular template centered on user)
 OSS = Operations Subsection of the ALEPH forces (vanilla Vedic units)
 
PF = Panzerfaust (two-shot anti-armor launcher)
 
QK = Qapu Khalqi (a Haqqislamite sectorial Army)
 Rambo/ramboing = spending most/all orders in a turn on one strong model
 
REM = Remote
 
SK = Skirmisher (unit class; infiltrators)
 SMG = Submachine Gun
 SS1/2 = Sixth Sense level 1 / 2
 
SWC = Support Weapons Cost (you get one for each full 50 points of the list format)
 
TAG = Tactical Armored Gear (the big robots)
 
TO = Thermoptic [Camouflage] / Tournament Organizer
 TR = Total Reaction
 Vanilla [list] = non-sectorial list
 
WB = Warband (class of expendable impetuous troops)
 WCD = War Contract Department (the Exrah part of the Combined Army)
 YAMS = Yet Another Mission System (a 
card-based objective system by IJW)
 YJ = Yu Jing
 
 
 Some additional abbreviations are covered by the 
ammunition chart. Some more common ones:
 
DA = Double Action (2 
ARM rolls on each hit suffered)
 E/M = Electromagnetic (instead of wounding, roll to disable electronics; E/M 
CCW rolls both for wounding and disabling electronics)
 
EXP = Explosive (3 
ARM rolls on each hit suffered)
 K1 = ? (target armor = 0 for this roll)
 Mono = Monofilament (roll against 
DMG 12, failed roll destroys model outright and removes from the table)
 N = Normal (no special effects)
 T2 = ? (Teseum round; each failed 
ARM roll causes 2 wounds)
 
 
 
 
Painting/modeling related:
 GS = "green stuff" (a two-part modeling putty)
 
NMM = Non-Metallic Metal (painting a metallic effect without actual metallic pigment)
 
OSL = Object-Source Lighting (painting light reflected from an object onto a miniature)
 PVA = Polivinyl Acetate [glue] (a.k.a. white glue, carpenter's glue)
 RMS = Reaper Master Series (a line of paints)
 VGC = Vallejo Game Color (a line of paints)
 VMC = Vallejo Model Color (a line of paints)