that'll be the day meaning

  • [American idiom]
    I don't believe that the day will ever come (when something will happen).
    Do you really think that John will pass geometry? That'll be the day.
    John graduate? That'll be the day!

  • [American slang]
    informal That will never happen. Joe wanted me to lend him money to take my girl to the movies. That'll be the day! "Wouldn't it be nice if we had to go to school only one day a week?" "That'll be the day!"

Related Words

  1. that very thing meaning
  2. that way meaning
  3. that will be the day meaning
  4. that will do meaning
  5. that will do. meaning
  6. that'll be the day! meaning
  7. that'll teach so! meaning
  8. that'll teach someone. meaning
  9. that's (just) the way it goes. meaning
  10. that's (just) too much! meaning
PC Version