/bluynd"suyd'/ , v.t., blindsided, blindsiding .
1. Sports. to tackle, hit, or attack (an opponent) from the blind side: The quarterback was blindsided and had the ball knocked out of his hand.
2. Informal. to attack critically where a person is vulnerable, uninformed, etc.: The president was blindsided by the press on the latest tax bill.
[ 1970-75; v. use of n. phrase BLIND SIDE ]