ABACIST
Ab"a*cist, n. Etym: [LL abacista, fr. abacus.]
Defn: One who uses an abacus in casting accounts; a calculator.
ABACK A*back", adv. Etym: [Pref. a- + back; AS. on bæc at, on, or toward the back. See Back.]
1. Toward the back or rear; backward. "Therewith aback she started." Chaucer.
2. Behind; in the rear. Knolles.
3. (Naut.)
Defn: Backward against the mast;-said of the sails when pressed by the wind. Totten. To be taken aback. (a) To be driven backward against the mast; — said of the sails, also of the ship when the sails are thus driven. (b) To be suddenly checked, baffled, or discomfited. Dickens.
ABACK
Ab"ack, n.
Defn: An abacus. [Obs.] B. Jonson.
ABACTINAL
Ab*ac"ti*nal, a. Etym: [L. ab + E. actinal.] (Zoöl.)