From uk.culture.language.english
(found at

This expression is interesting because "pear-shaped" has been long acknowledged as a description for an elegant cut of diamond. This pedigree would appear to give "pear-shaped" a positive description. "Pear-shaped" can also be used to describe the voluptuous anatomies portrayed by classical artists such as Poussin, Rubens, Raphael, or Rossetti.

"It went pear-shaped" is used in modern English to signify a comedic fiasco or similar disaster. In almost every circumstance, it refers to an undertaking or project that resulted in failure, but caused no grievous harm to anyone involved. Further, it provides a gentle suggestion that the fiasco was a result of nature and beyond the control of any specific individual. It is not regarded as vulgar or offensive.

Despite its common usage, the origin of the phrase remains obscure. Some sources attest that its origins lie in ballooning, and that a pear suggests the shape of a collapsed balloon. I can't find support for this etymology at

Others suggest that "pear-shaped" is rooted in aircraft terminology. The story goes that certain types of aircraft engine casings might go "pear-shaped" in the event of failure. Unfortunately, there is no convincing citation to accompany this claim.

Maths experts and "Quants" can be expected to attest that "pear-shaped" refers to a so-called "normal" or "Gaussian" distribution where the extremities of the distribution have become enlarged. In such a situation, improbable events would become much more probable. This is, at the moment, the preferred origin for "It's all gone pear-shaped".

Editor's note: If you have a definitive citation for "pear-shaped", please send email to