Example of a jocularly non-existent phenomenon, as many birds lack any teeth (having developed abill instead). Comparehorsefeathers andwhen pigs fly.
hen'stooth (pluralhen's teethorhens' teeth)
- (idiomatic) Anything not naturally occurring.
- Synonyms:rocking horse shit;see alsoThesaurus:rarity
- as rare as ahen's tooth
1992, Edwin Williamson,The Penguin history of Latin America, London; New York: Penguin Books,→ISBN,page183:Indeed, many of the Dutch in Pernambuco were won over to the Church of Rome, ‘whereas converts from Catholicism to Calvinism were as rare ashens’ teeth’.
something rare or hard to find
