Green’s Dictionary of Slang

the penis.

1942		in G. Legman Limerick (1953) 290: Meat-rationing did not terrify Miss Davey, / She got married to a sailor in the Navy, / For she knew between his legs / He had ham and he had eggs / A big wienie, and oodles of white gravy.
c.1944		Louis Jordan ‘Ration Blues’ 🎵 Baby baby baby, what’s wrong with Uncle Sam? / He’s cut down on my sugar, now he’s messin’ with my ham / I got the ration blues, blue as I can be.
2000		M. Manning Get Your Cock Out 36: Dandy started coming as soon as her star-crossed hero slammed in the ham.