Green’s Dictionary of Slang

eat one’s hat v.

to go back on one’s words, esp. to admit that a public statement was, in fact, wrong; one-off vars. include those at cits. 1923 and 1946.

[[UK]Rowlands Diogenes Lanthorne 14: If he be not throughly frenchified, and well peper’d for his venerie, then I will for seauen yeares eate hay with a horse].
[UK]Bridges Burlesque Homer (3rd edn) 15: I’ll eat my hat if you don’t scare him.
[UK]Dickens Pickwick Papers (1999) 563: Well, if I knew as little of life as that, I’d eat my hat and swallow the buckle whole, said the clerical gentleman.
[UK]Dickens Oliver Twist (1966) 370: A bad one! I’ll eat my hat if he is not a bad one.
[UK]Stirling Obs. (Scot.) 19 Aug. 1/5: Let them carry the same load as I have to do [...] and if they didn’t get a sickener of the Kaffir war in that time, I’d eat my hat.
[UK]Leaves from Diary of Celebrated Burglar 138/1: ‘I’ll eat my bloody ’at iv that ere’s anny ‘copper,’ ennywaiy,’ said Tom.
[UK]C. Hindley Life and Adventures of a Cheap Jack 216: Set these needles in your land and in about four months [...] you’ll find them all grown into crowbars! or I’ll eat my hat, then swallow my boots.
[UK] ‘’Arry on the River’ Punch 9 Aug. 57/1: As for that younger gurl, Carry, / I’ll eat my old boots if she isn’t dead gone on Yours bloomingly, ’Arry.
[UK]Dundee Courier 11 jan. 7/3: Weel, if that’s no a ‘sell’, I’ll eat my bonnet.
E.E. Money Little Dutch Maiden II 148: And if you don’t run up against him next day in Bond Street you may eat your hat!
[US]L.A. Herald 18 Jan. 2/2: Come in and talk with my wife. If she can’t keep you busy I’ll eat my boots.
[UK]E.J. Milliken ’Arry Ballads 38: If some of the swells didn’t ditto, I’ll eat my old hat, which it’s tough.
[US]Minneapolis Jrnl (MN) 5 May 2/2: If there’ eight ’undred Boers around there I’ll eat my boots.
[UK]New Boys’ World 22 Dec. 84: By Jingo, the old woman is an old man, or I’ll eat my hat!
[UK]Gem 16 Mar. 11: If this chap don’t go a full twenty, I’ll – I’ll eat my hat!
[US]O. Johnson Varmint 113: I’ll eat my pants!
[UK]E. Pound letter 3 July in Read Letters to James Joyce (1968) 36: And if you aren’t worth ten De la Mares I’ll eat my shirt.
[US]Coconino Sun (Flagstaff, AZ) 8 Nov. 1/5: Oh boy, if it isn’t 110 in the shade I’ll eat my little white bonnet.
[UK]R.D. Paine Fighting Fleets 143: This strange periscope, [...] – a Hun, or I’ll eat my hat.
[UK]‘Sapper’ Bulldog Drummond 179: I’ll eat my hat if that Frenchman isn’t Franklyn [...] or any other of the blamed names he calls himself.
[UK]Wodehouse Leave it to Psmith (1993) 571: And if it isn’t hidden somewheres in that McTodd’s shack down there in the woods I’ll eat my Sunday rubbers.
[UK]J.B. Priestley Good Companions 436: Mark my words – if we’re not up, right at top o’t’tree, a’most afore you can say Jack Robi’son, I’ll eat this cap. [Ibid.] 605: An’ if he’s not proposin’ marritch the morn’s morn an’ if she’s no gladly acceptin’ him, ah’ll go an’ eat ma best bonnet.
[US](con. 1920s) J.T. Farrell Judgement Day in Studs Lonigan (1936) 540: I’ll eat mine if I can’t drink you under the table.
[UK]E. Garnett Family from One End Street 128: I’ll eat my hat if it ain’t that author with all the tins.
[US]D. Runyon ‘It Comes Up Mud’ Runyon on Broadway (1954) 546: If they are able to get him to the races again he will eat his old wool hat.
[US]J. Evans Halo in Blood (1988) 226: He called him out [...] and killed him. I’ll eat my 1928 deputy-sheriff’s star if he didn’t.
[UK]I. Fleming Diamonds Are Forever (1958) 29: He’s not a diamond merchant, Sir [...] or I’ll eat my hat.
[UK]A. Sinclair Breaking of Bumbo (1961) 66: Just show me once you are right, and the Brigade’s wrong, and I’ll eat my bloody bearskin.
[WI]S. Naipaul Fireflies 325: Just look at that ring and if that is not a dollar sign I’ll eat my hat.
[US]M. Braun Judas Tree (1983) 109: I’ll eat your hat if he’s involved in these robberies.
[UK]Indep. Rev. 15 Jan. 5: If that man doesn’t have the face of a leader of a Nazi death squad [...] I’ll eat my hat.
[Aus]S. Maloney Sucked In 119: If we can’t get a sausage roll here [...] I’ll eat my socks.