Green’s Dictionary of Slang

1. the eye.

1833		‘Jerry Abershaw’s Will’ in Fal-Lal Songster in Spedding & Watt (eds) Bawdy Songbooks (2011) III 16: Let us vater vell our vinkers with some gin, O!
1842		Whip & Satirist of NY & Brooklyn (NY) 14 May n.p.: Berry [...] cut open the brow of the Doctor’s right winker.
1847		Bell’s Life in Sydney 10 Apr. 2/3: Ike sent in a left-handed spank on the winker.
1855		(con. 1840) Fights for the Championship 162: Caunt planted his left heavily on Brassey’s winker.
1857		Argys (Melbourne) 30 Nov. 5/5: The report [...] is copiously garnished with the slang of the prize ring; the various features of the brutal combatants being designated ‘ogles,’ ‘probosces,’ ‘smellers,’ ‘kissing traps,’ ‘winkers,’ &c.

2. a blow to the eye.

1825		Pierce Egan’s Life in London 2 Jan. 389/2: [H]e received a teazer on the nose, a winker between the ogles, and a clareted [sic] on his daffy passage .
1851		Bell’s Life in Sydney 31 May 1/6: The latter put his left on Massey’s eye, a winker that raised an ugly swelling.

3. the vagina [its supposed resemblance to a vertical ‘eye’].

1970

P. Bailey Trespasses 46: That silly cow of a Ruby had gone to his room to see how strong his light bulb was and within minutes she was shoving her naked winker at him.