Go pear-shaped is primarily a British idiom. We will examine the definition of the term go pear-shaped, where it came from and some examples of its use in sentences.
To go pear-shaped means to go wrong, to fail miserably, to go awry in a terrible fashion. To go pear-shaped may describe a situation in which finances suffer a sudden and catastrophic reversal, or a personal relationship takes a sudden and calamitous turn. The origin of the expression to go pear-shaped is in dispute. Some believe that the idiomatic phrase came into use in the 1980s, but others trace the phrase to the 1940s. They believe that the term originated with the Royal Air Force to describe pilots’ poor executions of loops in the air, ending up with pear shapes rather than a round shapes. Primarily a British phrase for many years, the idiom to go pear-shaped is being used more and more in North America, especially when describing economic or business downturns. Related phrases are goes pear-shaped, gone pear-shaped, going pear-shaped. Note that pear-shaped is properly rendered with a hyphen.
Above all, those who would succeed Theresa May might note that they will, if things go pear-shaped, need to rely on their friends to rescue them. (The Independent)
According to a source close to the couple, things had turned ‘pear shaped’ yet were allegedly working towards reconciling. (The Daily Mail)
Topshop flourished in the recession, after all, so why, in a period of relative prosperity, have things gone pear-shaped? (The Irish Times)
“I feel like I held it together pretty well in the middle of the round when things could have all gone pear-shaped,” Law said. (The Virginian-Pilot)