Green’s Dictionary of Slang

a male prostitute; also attrib.

1956		H. Gold Man Who Was Not With It (1965) 87: No F.O.B.’s, C.O.D.’s, junkies, lushes, agitators.
1972		(ref. to late 1950s) B. Rodgers Queens’ Vernacular 112: During the late ’50s, house calls were made by the delivery boy or the COD boy (cock on delivery) with his prominently displayed packages.
1986–7		Maledicta IX 143: The COD (cock on delivery) lads chiefly go on the batter (walk the streets) making gay pennies as cash ass.