Green’s Dictionary of Slang

1. (also cockle-muscle) the penis.

1969		H. Fanning Screwy Cruise n.p.: ‘Now go and give Vera some! I think that she will welcome cockle after that strapping!’.
1970		‘Carlton Miller’ [Avram Davidson] Incest Street 187: [H]is big, hard cockle-muscle [...] jammed its swift way up deep inside of her jam-sweet snatch.
1985		M.L. Rong Nymph about Town n.p.: ‘Come on, George, let’s see your little cockle get big and fat, like it used to do when you watched me undress’.
2006		J. Roberts ‘Farm Boy thumbs a Ride’ in www.nifty.org 18 Aug. 🌐 ‘Pretty black hair all over from toes to cockle’.
2022		‘New Daddy’ in www.nifty.org 29 Aug. 🌐 Mason’s cute cockle was once again at full mast.

2. the female genitals.

1660		‘Megg. Spencer’ A Strange and True Conference 7: The spanish mode of shaving off all the wenches hairs of their Commodities [...] the Barber [...] is to have an over-plus Fee [...] call’d Cockle-de-moy.
1978		R. Belben Dreaming of Dead People in Reynolds Erotica (1990) 320: Can it be the cunt’s lips curl into a grin. Smile cockle smile [...] In medieval vernacular cockle was a name for cunt.

3. a cuckold.

2005

‘Professor Aalto, His View’ in literotica.com 27 Dec. 🌐 I knew Marge was screwing around on me. Being the campus cockle is embarrassing.