yabos UK /ˈjæbəʊz/US /ˈjæboʊz/ noun[plural only]1 •(slang) A woman's breasts.Boon: You going out tonight, Otter? Otter: Uh-huh. Boon: Norma? Otter: No, let me give you a hint. She's got a couple of major-league yabos. — 1978