See also: Appendix:Variations of "ar"
AR (not comparable)
- (statistics) Initialism of .
- (countable, weaponry) an AR-15 personal semi-automatic rifle, M-16 assault rifle, M-4 carbine, derivative or related gun; the Armalite AR family and derivatives.
- (biochemistry) Initialism of .
- (accounting, uncountable or plural only) Initialism of .
- (sports, countable) area record: best achievement among those by persons from a given continent
- (sports, US, countable) Abbreviation of ., national record for the United States.
- (crime) Initialism of .
- (computing, chiefly uncountable) Initialism of .
- (countable) Initialism of .
- (fan fiction) alternate reality
- (meteorology) Initialism of .
- (emergency medicine) Initialism of .
- (philately, postal service) Initialism of .
- (gun): AK
- Postal abbreviation of
- (Arkansas): Ark. (standard, not postal, abbreviation)