fatty boombalatty noun2 •(slang, offensive) An extremely obese person.Fatty Jones proposed it over his shoulders as he waddled along in the dust. The rest whoop wild agreement. "Fatty, Fatty, boom-a-latty," they screeched joyously.[…] — 1908 •(slang) An extremely thick joint or blunt of marijuana. formsfatty boombalatties