Green’s Dictionary of Slang

(US) the female breasts.

1961		M. Terry Old Liberty (1962) 43: A little wife with nice jabongoes to kiss me hello every night.
1991		M. Terry Old Liberty 33: A little wife with nice jabongoes to kiss me hello every night.
2006		‘Bobbie Bazooms’ Office Slut 🌐 These are the words to call your boobs from now on [...] Tits, titties, boobs, boobies [...] Knockers, melons, jugs, jamambos [...] Hooters, headlights, honkers.
2008		Urban Dict. 9 June 🌐 Jabongos. Referring to the natural and plentiful breasts of a C-cup or larger, only when in the act of copulating in the valley of cleavage.