British slang for events taking an unexpected turn for the worse.

(See also "Pete Tong")

When something potentially good has gone disastrously wrong. Similar to "taking a turn for the worst" or going "pete tong".

When something has 'gone pear-shaped', it means something has gone wrong or not according to plan.

Unexpectedly gone wrong or gone awry.

UK slang (London)

To go wrong, to be victims of Murphy's Law. Often heard for the lips of actors in Brit crime flicks and cop shows Origin obscure.

British slang term, used to describe when a situation has gone bad....I've no idea where it originates, but that's how it's used.

When the majority of things appear to be negative. Like the shape of a pear, the majority is at the bottom (bad) and little is at the top (good).