eat your hat

eat (one's) hat

A humorous action that one will allegedly take if something very unlikely happens. Kevin is always late, so if he actually shows up on time, I'll eat my hat.
See also: eat, hat
Farlex Dictionary of Idioms.

eat your hat

mainly BRITISH, OLD-FASHIONED
If you say that you will eat your hat if a particular thing happens, you mean that you do not believe that it will happen. I will eat my hat if the Social Democrats get in at the next general election. He has promised to eat his hat if he is wrong.
See also: eat, hat
Collins COBUILD Idioms Dictionary, 3rd ed.
See also:
  • see the funny side (of something)
  • see the funny side of something
  • sliced bread
  • the best thing since sliced bread
  • greatest thing since indoor plumbing
  • greatest thing since sliced bread
  • greatest thing since sliced bread, the
  • indoor
  • meals rejected by Ethiopians
  • reject
References in periodicals archive
SUGAR BOWL: Should you ever threaten to eat your hat, make sure the milliner is Alison Tod.
So, prepare to eat your hat - this is a decent adventure made all the more appealing now it's on video.
Well, next time you're cooking up a quick pasta, you can eat your hat. Cunningly fashioned into little sombreros, Il Pastaio Matto Sombreroni are handmade from durum wheat, tomatoes, beetroot, saffron and spinach.