The Collaborative International Dictionary of English v.0.48:
Winker \Wink"er\, n. 1. One who winks. --Pope. [1913 Webster] 2. A horse's blinder; a blinker. [1913 Webster]WordNet (r) 3.0 (2006):
winker n 1: a person who winks 2: blind consisting of a leather eyepatch sewn to the side of the halter that prevents a horse from seeing something on either side [syn: winker, blinker, blinder]