Definition of I'll eat my hat in US English:

I'll eat my hat

phrase

informal
  • Used to indicate that one thinks the specified thing is extremely unlikely to happen.

    ‘if he comes back, I'll eat my hat’
    • ‘If they can do it without relying on underlying axioms of homophobia and bigotry, then I'll eat my hat.’
    • ‘If there's a child anywhere that'll like this I'll eat my hat.’
    • ‘And if that doesn't spark some debate, I'll eat my hat.’
    • ‘If he's not snapped up by Hollywood I'll eat my hat.’
    • ‘If London is still standing in the year 2020, I'll eat my hat.’
    • ‘But if you like the samples, you'll love the original stuff, or I'll eat my hat.’
    • ‘If computers come with CD drives 50 years from now, I'll eat my hat.’
    • ‘If you do all that, and still don't get an A, I'll eat my hat.’
    • ‘It's so secret I haven't a clue where or when it is but I'll tell you this: if I don't get there, I'll eat my hat.’
    • ‘If places like Scarborough and Doncaster don't benefit from that I'll eat my hat.’