aback

aback is an   Adjective

Definition:

[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.

Synonyms: