Green’s Dictionary of Slang

(Ling. Fr./Polari ) the number two.

1861		(con. 1840s–50s) H. Mayhew London Labour and London Poor III 206/2: We could average our duey bionk peroon a darkey, or two shillings each, in the night.
1893		P.H. Emerson Signor Lippo 44: One of the troupe intimated a whip round for the cook, so we gave her due soldi apiece.
1984		Partridge DSUE (8th edn) 331/1: dooee, occ. dooe; doee; duey. Two [...] mid-C19–20.
2019		P. Baker Fabulosa 291/1: dewey, dooe, dooey, duey two.
2023		R. Milward Man-Eating Typewriter 4: In duey-chenta setta-daitcha-heksa junos (276 days, for those without the lingo).