1. a statement made when you are positive that something will happen; a phrase telling the kind of thing that one would do if a very unlikely event really happens

1. If we don’t win this basketball game by at least twenty points, I'll eat my hat.

2. If we get there on time, I’ll eat my hat.

3. I’ll eat my hat if you get a raise.

4. He said he’d eat his hat if she got elected.