QUOTE (Augeas @ Mar 13 2008, 10:34 PM)

What's the significance of the pear?
Piriform means pear shaped - as in "It's all gone pear shaped". From
Wikipedia:
QUOTE
mostly limited to the United Kingdom and Australasia. It describes a situation that went awry, perhaps horribly wrong. A failed bank robbery, for example, could be said to have "gone pear-shaped". The origin for this use of the term is in dispute. The OED cites its origin as within the Royal Air Force; as of 2003 the earliest citation there is a quote in the 1983 book Air War South Atlantic (ISBN 0-283-99035-X). Others date it to the RAF in the 1940s, from pilots attempting to perform aerial manoeuvres such as loops. These are difficult to form perfectly, and are usually noticeably distorted—i.e., pear-shaped.