Green’s Dictionary of Slang

1. (US) the penis.

1916		H.N. Cary Sl. of Venery IV (t/s) n.p.: penis Dingle.
1966		M. Rumaker Exit 3 and Other Stories 65: You think I’m hot to see a boogie’s dingle, the way Billy is?
1978		S. King Stand (1990) 250: I’m on a hunger strike! [...] You’ll eat my dingle before I eat anything you bring me, you fuckin deaf-mute retard asshole!
1996		(con. 1964-65) B. Thorpe Sex and Thugs and Rock ’n’ Roll 216: His little dingle bouncing in time to the music.
2010		L. Berney Gutshot Straight [ebook] ‘I could just shoot his dingle off’.

2. in generic use, used of a person.

2012

(con. 1980s) I. Welsh Skagboys 85: Ah kin vaguely hear Goagsie arguing wi one or baith ay these dinguls in the corner.