Pronunciation: (u-bak'),[key] —adv. 1. toward the back.
2. Naut.so that the wind presses against the forward side of the sail or sails.
3. taken aback, surprised and disconcerted: I was taken aback by his harsh criticism.
—adj.Naut. 1. (of a sail) positioned so that the wind presses against the forward side.
2. (of a yard) positioned so that its sail is laid aback.