Aback

Part of speech: noun (n.)

An abacus. [Obs.] B. Jonson.

Part of speech: adverb (adv.)

1. Toward the back or rear; backward. "Therewith aback she started." Chaucer.

2. Behind; in the rear. Knolles.

3. 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.