fatty /ˈfæt.i/adjective 5noun 3forms 3 adjective5 •Containing, composed of, or consisting of fat.fatty tissues •Sometimes, especially, containing excess fat.That means eating fruits and vegetables and cutting back on fatty foods. — 2002 •Of or related to fat.On the sixth, stools black, fatty, viscid, fetid; slept, more collected. — 1849 •Like fat; greasy. •(slang) Literally or figuratively large.Be careful of the taxi drivers out there though, I've heard they sell you drugs, drop you off at your hotel and then dob you in to the Thai Police to get a fatty reward! — 2007 noun3 •(slang, offensive) An obese person.It's hardly surprising, when it has to support that enormous gut! Lose some weight, fatty! •(slang) A large marijuana cigar; a blunt.We went to Plaster Creek, smoked a fattie, and emerged doing somersaults and cartwheels and laughing. — 2004 •A type of game played with marbles. formsfatties · fattier · fattiest