See also: Appendix:Variations of "ar"
AR (not comparable)
- (statistics) Initialism of autoregressive.
- (countable) an AR-15 personal machine gun, M-16 assault rifle, M-4 carbine, derivative or related gun
- (accounting, uncountable or plural only) Initialism of accounts receivable.
- (sports, countable) area record: best achievement among those by persons from a given continent
- Initialism of armed robbery.
- (computing, chiefly uncountable) Initialism of augmented reality.
- (countable) Initialism of aspect ratio.
- (fan fiction) alternate reality
- (meteorology) Initialism of atmospheric river.
- (emergency medicine) Initialism of artificial respiration.
- (gun): AK
- Postal abbreviation of
- (Arkansas): Ark. (standard, not postal, abbreviation)