Green’s Dictionary of Slang

1. a fat person, esp. as a nickname.

1825		C.M. Westmacott Eng. Spy I 262: FattyT--, better known as the sixpenny schoolmaster: a little fat man remarkable for his love of good living.
1847		J.M. Field Drama in Pokerville 102: Back went old fatty against the centre-table.
1858		R.S. Surtees Ask Mamma 470: The fatties, and funkers, and ticklish forelegged ones, begin who-a-ing and g-e-e-ntly-ing to their screws.
1860		R.S. Surtees Plain or Ringlets? (1926) 38: Hitherto the fatties have had it all their own way.
1874		F.C. Burnand My Time 103: The Biffords, whose names [...] were ‘Fatty’ and ‘Puggy’.
1886		N.-Y. Tribune 27 Dec. 4/3: Is Mr ‘Fatty’ Walsh a truly good man?
1898		J.D. Brayshaw Slum Silhouettes 215: ‘Wot cher, Jumbo!’ ‘Wot cher, Fatty! Seed Cocky Brown lately?’.
1903		St Louis Republican (MO) 30 Aug. 52/2: If you see Frisco Fatty give him my regards.
1910		O. Johnson Varmint 243: ‘Who’d go in at center?’ ‘Fatty Harris, perhaps.’.
1916		Firefly 9 Dec. 1: It was easy to get to fatty’s little feed that he had prepared for himself.
1918		F. Dunham diary 20 Aug. Long Carry (1970) 202: ‘Fatty’ Lewis, who was helping out with stores.
1925		S. Lewis Arrowsmith 23: Fatty was of all the new Freshman candidates the most useful to Digamma Pi.
1937		J. Curtis You’re in the Racket, Too 284: She’d have to find some other old fatty again.
1953		W. Eyster Far from the Customary Skies 44: Sore? You thinnies may be as sore as us fatties, but sure ain’t as much sore.
1965		T. Wolfe Kandy-Kolored Tangerine-Flake Streamline Baby (1966) 65: Some kind of old short-armed fatty [...] with a spread collar shirt and a bald olive skull with strands of black hair.
1975		D. Goines Inner City Hoodlum 7: A teenage fatty, one of those kids who everyone would pick on.
1999		Indep. Rev. 10 Sept. 11: Fatties, blacks and cripples are all simply there to make Mox look good.
2001		K. Sampson Outlaws (ms.) 94: They was in The Monty the other night, trying to pull these two fatties.
2011		‘Jack Tunney’ Split Decision [ebook] One fat guy sent another backwards, but the crowd of bloodthirsty savages behind him threw fatty back into the mix.
2019		Star Gaz. (Elmira, NY) 27 Feb. 10B/4: I heard Glen beck call film-maker Michael Moore a ‘fatty-fatty fatso’.

2. as term of (derog.) address.

1873		Leeds Times 31 May 7/6: I have heard Arthur Orton addressed as ‘Fatty’ [...] Orton by his school-fellows.
1882		E. Nye Forty Liars (1888) 31: Hulo, Fatty, is that you?
1907		W.M. Raine Bucky O’Connor (1910) 21: What’s the matter, Fatty?
1939		P. Cheyney Don’t Get Me Wrong (1956) 10: Why don’t yu take your weight off your feet an’ sit down, Fatty.
1944		N. Davis Rendezvous with Fear 47: Hey, fatty!
1963		N. Dunn Up the Junction 14: Fatty, you’re nine stone three.
1983		Beano 1 Oct. 10: Come and get this lovely cream cake, Fatty!

3. (Aus.) as (supposedly) joc. nickname of an very thin person.

1904

Sydney Sportsman (Surry Hills, NSW) 1 June 3/3: A ragged, red-nosed, shivering newsboy [...] turned and yelled in ear splitting tones to his mate [...]: ‘Hay, Fatty’ (the said mate was a fit model for a painter with ‘Starvation’ for a subject).

4. a fat tyre, as used on bicylcles and automobiles.

1991

R.G. Barrett Between the Devlin 142: [A] blue 1967 Ford with a noisy exhaust system and fatties.