All G&A a/c A/D a/r A/S a/s/l C/A See all meanings Idioms and phrases over a collision study course idiomAbout a thousand bce, in Byblos together with other Phoenician and Canaanite centres, the signal was supplied a linear variety (3), the source of all afterwards forms. In Semitic languages this signal was named alephIn algebra, the letter a in a