Green’s Dictionary of Slang

dangle n.

1. the penis.

[[UK]Tilly Touchitt 13: Such a strange, long, lolloping dangle-dumdee].
Kerouac On the Road 44: On the wall was a nude drawing of Dean, huge dangle and all.
[US]Baker et al. CUSS.
[UK]S. Berkoff East in Decadence and Other Plays (1985) 60: Thought I tasted something very strange on his straining dangle.
[UK] (ref. to WWI) Partridge DSUE (8th edn) 290/2: dangle-parade. A ‘short-arm’ inspection: NZ soldiers’: WWI.
[UK]S. Berkoff West in Decadence and Other Plays (1985) 116: I’m channelled up the escalator still holding my dangle.
[UK]Guardian G2 5 July 8: Of all the pleasures some may find in the male dangle, I venture that the view is not among them.

2. (US) an impotent man.

[US]J. Roe The Same Old Grind 201: ♣Who was you with? Some old dangle who can’t get it up?’.

In compounds

dangle queen (n.) [-queen sfx (2)]

(US gay) one who wears clothes that deliberately emphasize the penis, or who exposes the genitals.

[US]B. Rodgers Queens’ Vernacular 60: dangle queen 1. gay exhibitionist. ‘Johnny was a dangle queen; he used to get busted for showing his schwantz to little old ladies in the vestibule.’ .. 2. man who wears tight trousers in order to show off his crotch contours.
[US]H. Max Gay (S)language 11: Dangle queen—gay who wears tight pants or exposes himself completely.

In phrases