expression🎓 English idiom

when pigs fly

never

What it means

Used to say that something will never happen, because it is utterly impossible or extremely unlikely. It is a sarcastic way of dismissing a claim or promise.

Examples

  • He'll clean his room when pigs fly.
  • Sure, she'll apologise when pigs fly.
  • They'll lower taxes when pigs fly, if you ask me.
  • You think he'll be on time? When pigs fly!

Where it comes from

The phrase belongs to a family of old 'impossibility' sayings and appears in various forms from the 17th century onward, including in Scottish proverbs. The image of a pig in flight is deliberately absurd.

Related idioms

#once in a blue moon#a long shot#at the drop of a hat#the grass is always greener

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