Aviation is full of acronyms that are very often not obvious.
Where can we look if we come across one that we aren't familiar with?
If you have come across an acronym that you aren't familiar with, here are a few places to look:
Wikipedia also presents a nice list: List of aviation, aerospace and aeronautical abbreviations
From there, you can get to the relevant article for further details.
FAA - Order JO 7340.1Z Contractions (561 p.)
This handbook contains the approved word and phrase contractions used by personnel of the Federal Aviation Administration (FAA) and other agencies th at provide air traffic control, communications, weather, charting, and associated aviation communication services. Also contained are aircraft-type designators; civil aircraft company three-letter identifiers and telephony designator assignments; aircraft nationality assignments; and civil/military aircraft-type designators
AAA - All Aviation Abbreviations (55 p.)
A list of more than 7000 aviation abbreviations and acronyms are commonly used in aviation and may be found throughout aviation legislation, operational manuals, in the AIP, on associated aeronautical charts and maps, in NOTAMs, in AIP supplements in meteorological messages etc. The abbreviations and acronyms have been sourced from and are used in various areas, such as ICAO, AIP, IATA, FAA, Metar, Taf, Notam and Jeppesen and many other documents.
Aviation Electronics Glossary (Rockwell Collins) (At Scribd)
Avionics-ese. Sometimes called AV-Speak. It’s a confusing, sometimes frustrating language. That’s why your friends at Rockwell Collins created this handy. compendium of acronyms, terms and definitions. We hope it helps.