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 class idiom[ C/U ]   music   plural A’s or As in Western tunes, the sixth note in the size (= series of notes) that starts to the note C, or perhaps a list of notes determined by this ObserveA is often utilized to denote something or anyone of a better or mor