Per suggestion of CessnaCitationX in the ‘Flight Spotting’ topic, here is the first installation of common “Lingo” used on FlightAware. Everyone please feel free to contribute.
IFR - Instrument Flight Rules
VFR - Visual Flight Rules
FA - FlightAware
FL - Flight Level
nm - nautical miles
kts - knots (nautical miles per hour) [Never ‘knots per hour’ (excepts for knitters)]
Don’t forget the newly added:
BIL - Brother in-law
FIL - Father in-law
IMC - Instrument Meteorological Conditions
VMC - Visual Meteorological Conditions
A/C - Aircraft
ILS - Instrument Landing System
ACAS - Airborne Collision and Avoidance System
ACF - Area Control Facility
MAP - Missed Approach
GA - General Aviation
MTOW - Maximum Take Off Weight
H&H - Hot & High, Also: Hot & Heavy
VR - Takeoff Rotation Velocity
VREF - Reference Velocity
VOR - VHF Omni Range
Off the top of my head and in the time allowed. 
Regards,
James
TLA - Three Letter Acronym
Would it be possible to put the lingo into the FAQ’s?
“Excuse me, sir. Seeing as how
the VP is such a VIP…shouldn’t we keep the PC on the QT,
'cause if it leaks to the VC…he could end up an MIA,
and then we’d all be put on KP.”
F.U.= “I disagree with your opinion.”
J.K.! 
(J.K.=“Just Kidding”)
We’ll create a glossary of terms soon. It will probably be maintained by staff, but we’ll be happy to take suggestions from this thread for entries.
ACARS - Aircraft Communications Addressing and Reporting System
MEL - Minimum Equipment List
NOTAM - Notice For Airman
RVR- Runway Visual Range
FSS - Flight Services Station
TAF - Terminal Area Forcast
DUATS - Direct User Access Terminal
RVSM - Reduced Vertical Separation Minimum
MVFR - Marginal Visual Flight Rules
PIC - Pilot In Command
CFI - Certified Flight Instructor
CFII - CFI Instruments
MEI - Multi Engine Instructor
ATP - Airline Transport Pilot
CTO - Control Tower Operator
then there’s always SOL and WAG - (both self explanatory)
FAR = Federal Aviation Regulation
As in FAR 1.2
AIM = Aeronautical Information Manual
As in AIM Appendix 3.
Taxi - not ground transportation but airplane movement on the ground
LIFR Lower Instrument Flight Rules (ceilings less then 500 feet)
VLIFR Very Low Instrument Flight Rules (Ceilings less then 200 feet)
MVFR - Marginal Visual Flight Rules (ceilings more then 1000 and less then 3000 feet)
Airport Identifier - 3 or 4 charactor letter identifying the aiport (MBO or KMBO)
RVR Runway Visual Range
TAF Terminal Aerodrome Forecast (Weather forecast)
ASOS Automated Surface Observation Station (computer reporting weather station)
ATIS Automated Terminal Information Service (Pilots use this to get airport landing information)
POH Pilot Operating Handbook
SM Statue Mile
NM Nautical Mile
Waypoint-GPS fix ?(correct me if I’m wrong)
Fix-intersection of 2 (or more) radials
Radials-lines (of radio waves) going out from VORs. Pilots track these for navigation
VHF-Very High Freq
UHF-Ultra High Freq
Jetroute-(i.e. J525, J1) For Navigation FL180 and up
Victor Airway-are routes
Class A airspace-FL180 to FL600
Class B airspace-exstends 30 nm from major arpt(like upsidedown wedding cake) up to 10,000 MSL
Class C airspace-exstends 10nm from arpt (ceiling is 5000 AGL)
Class D airspace-exstends 5nm from arpt (cylinder) usually 2500AGL (ceiling may vary though)
Class E airspace-controlled
Class G airspace-uncontrolled (not much of it and going away fast)
AGL-Above Ground Level
ASL-Above Sea Level
MSL-Mean Sea Level
TRSA-Terminal Radar Service Area
TAC-Terminal Area Chart
TAS-True airspeed
GS-Ground speed
IAS-Indicated Air Speed
AWOS-Automated Weather Obsevation Service
CT-Control Tower
APP-Approach
Dep-Departure/Departing
OROCA-Off Route Obstacle Clearance Altitude
RMI-Radio Magnetic Indicator
ARTCC-Air Traffic Control Center
SVFR-Special VFR
METAR-this gives the Weather
CAS-Calibrated Airspeed
FAF-Final Approach Fix
I’ll post some more when they come to mind.
STAR-Standard Arrival Procedure
DP-Departure Procedure
IAP-Instrument Approach Procedure
A/FD-Airport/Facility Directory
DME-Distance Measuring Equipment
Nor the ever popular:
MIL - Mother in-Law
SIL - Sister in-Law
and the famous:
SCTW - Second Cousin, Twice Removed!
Rather than attempt to rebuild the wheel, why not just post a link to: gps.tc.faa.gov/glossary.html somewhere in the FAQs?
Regares,
James
Thanks for the GLOSSARY. This seems to be a bit more detailed than THE LINGO was intended to be! Maybe like a “top 100 most used” list would be best.
Actually, I doubt there is an “all inclusive” glossary outside FAR / AIMS
The above link didn’t include the flight categories
LIFR Lower Instrument Flight Rules (ceilings less then 500 feet)
VLIFR Very Low Instrument Flight Rules (Ceilings less then 200 feet)
These terms do show up in the airport weather on My Flight Aware page for airports you are watching. You’d be surprised how many pilots have not heard of these categories.
The significance of these categories is that they are below “alternate” qualifications using the minimim 1,2, 3 rule.
Allen
For you OT’s (Old Timer’s) from the great WWII era:
SNAFU…Situation Normal, All Fouled Up!
And that great mess hall favorite SOS…Creamed chipped beef (I cleaned up the language ) On a Shingle!
This thread is FUBAR…
I recommend the world famous 7340.1:
The FAA Contractions Manual
I recommend Chapter 2, for that wonderful light reading that leads to much knowledge.
Knowing contractions, especially for weather, will prevent the always exciting
RTB AWX…
We added a link to the FAA’s acronym list in the FAQ.
By popular demand:
BFE - BumbleF*#$ Egypt…aka, middle of nowhere