Green’s Dictionary of Slang

1. (US, also donkey-cock) a notably large penis; usu. as adj. donkey-dicked, having a large penis [US successor to donkey prick under donkey n.].

1970		T. Southern Blue Movie (1974) 227: Trousers off now, his rude donkey-cock extended grotesquely in front of him, chasing our heroine about the room.
1980		Maledicta IV:2 (Winter) 189: Dick or dickie [...] is also short for [...] donkey-dick, which is a well-known undoubtdly male animal, well-hung or well-endowed with family jewels.
1985		(con. 1968) D.A. Dye Citadel (1989) 286: We would stretch our sector as far as we could until it got dark [...] Very simple. Neat and tidy, Very logical. Hard as a petrified donkey dick to pull it off. But very simple and logical.
1999		E. Bunker Mr Blue 90: The dog that said that’s got a mama that sucks donkey dicks.
2001		J. Stahl Plainclothes Naked (2002) 241: Zank nudged Manny in the stomach with his gun. ‘Don’t be a hero, donkey-cock.’.
2010		J. Ellroy Hilliker Curse 18: One woman was really a man witjh an implied donkey dick.
2015		L. McInerney Glorious Heresies 223: The fellas had donkey dicks and dead eyes.

2. (US prison) a hot dog.

1975		J. Wambaugh Choirboys (1976) 142: We wake our prisoners at five A.M. and serve them meals of red death, Gainesburgers and donkey dicks.
1986		J. Ellroy Silent Terror 67: The mess-hall slang for Salisbury steak, hot dogs and breakfast jelly was respectively, ‘Gainesburgers,’ ‘donkey dicks’ and ‘red death’.

3. (US milit./prison) sliced cold cuts.

1965		‘A New Dictionary of Army Language’ in Yeah mag. No. 10 donkey dick and peanut butter: field rations cold or uncooked.
2000		Other Side of the Wall: Prisoner’s Dict. July 🌐 Donkey Dick: Sliced cold cuts.

4. (US) in fig. use, a problematic situation.

1965

‘A New Dictionary of Army Language’ in Yeah mag. No. 10 mess of chopped up donkey dick, it looks like a: a reference to a messy situation.

5. (N.Z. prison) a whole luncheon sausage.

2001

D. Looser Boobslang [U. Canterbury D.Phil. thesis] 60/1: donkey dick n. a roll of luncheon sausage.