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 ]   tunes   plural A’s or As in Western audio, the sixth Take note in the dimensions (= series of notes) that starts to the Observe C, or even a set of notes based upon this Notice[4] The Roman type ?a? is present in most printed substance, a