1760. Sterne, Tristram Shandy, ch. cxxvi. A chapter of chambermaids, green gowns, and old hats.
1785. Grose, Vulg. Tongue, s.v. [‘Because often felt.’] See also Top Diver.
1811. Lexicon Balatronicum, s.v.
3. (Scots’).—A prostitute of long standing. For synonyms, see Barrack-Hack and Tart.
To eat one’s hat (or head), verb. phr. (common).—Generally, I’ll eat my hat. Used in strong emphasis. See Eat.
1836. Dickens, Pickwick, xlii., 367. ‘If I knew as little of life as that, I’d eat my hat and swallow the buckle whole,’ said the clerical gentleman.
1837. Dickens, Oliver Twist, ch. xiv. Even admitting the possibility of scientific improvements being ever brought to that pass which will enable a man to eat his own head, Mr. Grimwig’s head was such a particularly large one that the most sanguine man alive could hardly entertain a hope of being able to get through it at a sitting.
1844. J. B. Buckstone, The Maid with the Milking Pail. If you are not as astonished as I was, I’ll eat old Rowley’s hat.
1876. Hindley, Adventures of a Cheap Jack, p. 216. I’ll eat my hat.
1887. E. E. Money, Little Dutch Maiden, II., viii., 148. And if you don’t run up against him next day in Bond Street, you may eat your hat!