Kenneth G. Wilson (1923–). The Columbia Guide to Standard American English. 1993.
take aback (v.)
has two current Standard senses: a literal nautical one meaning what happens to square sails (and to the ship that carries the sails) when the wind suddenly begins to blow on the wrong side of the sails, as in The wind suddenly veered and took the ship aback, causing her to slow and wander off course, and a generalized sense, “to be taken by surprise,” as in Their unreasonable anger took us both aback.
