All G&A a/c A/D a/r A/S a/s/l C/A See all meanings Idioms and phrases on the collision study course idiom[ C/U ]   songs   plural A’s or As in Western audio, the sixth note in the scale (= series of notes) that starts to the Take note C, or even a set of notes determined by this Take noteWhen the ancient Greeks adopted the alphabet, they had no