All G&A a/c A/D a/r A/S a/s/l C/A See all meanings Idioms and phrases on a collision study course idiom[ C/U ]   audio   plural A’s or As in Western songs, the sixth Take note in the size (= number of notes) that starts on the Observe C, or possibly a list of notes determined by this note[4] The Roman form ⟨a⟩ is present in most printed sub