Green’s Dictionary of Slang

winkle n.1

(usu. UK juv.) a (small) penis.

[UK]Farmer & Henley Sl. and Its Analogues.
[UK] ‘She Wore No Blouse’ in Bold (1979) 204: My boy, the pimple / On the end of your winkle / Will grow just like a red, red rose.
[US]Trimble 5000 Adult Sex Words and Phrases.
[UK]Viz June–July 25: I love the taste of a hot winkle.
[UK]P. Baker Fabulosa 299/1: winkle a small penis.

In phrases

have (something) on the winkle (v.)

to be obsessed by something.

[UK]K. Amis letter 19 May in Leader (2000) 390: I’m longing to know the Swedish for phrases like ‘You’ve got this “rude” business on the winkle.’.
K. Amis Green Man 118: Look, Dad, for some reason you’ve got death on the winkle.
[UK]Partridge DSUE (8th edn) 1343: [...] since ca. 1920.
elderly gentleman, London East End ‘Is that a boy dog? [points to dachshund] I don’t understand how he doesn’t bang his winkle when he jumps up on to the pavement’.
spit the winkle (v.)

(Aus.) to squirt water from one’s anus (a surfer’s ‘party trick’).

[Aus]Tracks (Aus.) Dec. 78: [caption] One of the most notorious surfers’ party tricks – spit the winkle.
[Aus]Tracks (Aus.) Mar. 3/2: [I]n your excellent salute to the ’80s, there’s a photo of a dude dropping a brown-eye. You have said he’s ‘spitting the winkle’. [...] The man in question is actually squirting water from his bottom.