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 ]   audio   plural A’s or As in Western songs, the sixth note in the dimensions (= series of notes) that commences within the Be aware C, or a list of notes based upon this Notice[four] The Roman sort ?a? is located in most printed substance,