Aback (&adot_;băk), adv. [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.[1913 Webster]
2. Behind; in the rear. Knolles.[1913 Webster]
3. (Naut.) Backward against the mast; -- said of the sails when pressed by the wind. Totten.[1913 Webster]
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.[1913 Webster]
Aback (ăb&aitalic_;k), n. An abacus. [Obs.] B. Jonson.[1913 Webster]