adv.1 archaic backwards, behind.
2 Naut. (of a sail) pressed against the mast by a head wind.
Phrases and idioms:
take aback
1. surprise, disconcert (your request took me aback; I was greatly taken aback by the news).
2 (as taken aback) (of a ship) with the sails pressed against the mast by a head wind.
Etymology: OE on b{aelig}c (as A(2), BACK)