Lewis & Short

1. AC, a Latin root, denoting

    (
      1. 1. ) sharp and (
      2. 2. ) quick, kindred with the Greek ἄκρος and ὠκ-ύς, Sanscr. ācu (= celeriter). Hence the Latin acer, acies, acuo, acus, acutus, aquila, accipiter, acupedius (prob. also equus), ocior, and oculus.