ANNO ANTE CHRISTUMglossary / ANNO ANTE CHRISTUM ANNO ANTE CHRISTUManno ante Christum (an-oh an-tee kris-t[schwa]m), adv. [Latin] In the year before Christ. ¡ª Abbr. A.A.C. Contributor Carl, Chinese legal translator, specializes in translating legal documents pertaining to complex business disputes.