- (1990s) From the image of a solid rectangle 'slipping down' into a pear shape, thus 'the bottom drops out'. — Jonathon Green, Cassell's Dictionary of Slang, second edition, Weidenfeld & Nicolson, London, 2005
- Presumably from the image of a balloon or football losing its spherical shape after puncturing. — Tony Thorne, Dictionary of Contemporary Slang, third edition, A & C Black, London, 2005
go pear-shaped (third-person singular simple present goes pear-shaped, present participle going pear-shaped, simple past went pear-shaped, past participle gone pear-shaped)
- (Britain, New Zealand, idiomatic) To go wrong; to go awry.