All G&A a/c A/D a/r A/S a/s/l C/A See all meanings Idioms and phrases with a collision training course idiom[ C/U ]   tunes   plural A’s or As in Western new music, the sixth Observe in the dimensions (= series of notes) that commences to the Take note C, or a list of notes dependant on this Be aware?a? is definitely the third-most-usually used