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).

originates from: when a woman gets older, her breasts shrivel up and arse blooms out, giving her a figure shaped like a pear

means: its all gone wrong

see also: tits up

if something has gone wrong, it has gone pear shaped

To become pear shaped,or gain hips and an ass

An unfortunate occurrance common in middle aged wives in which their derriere grows disproportionately large wen compared to both their breasts and their shoulders.

Become overweight. Increased girth in stomach and butt areas. Lost any semblence of a decent figure.

gained weight; got fatter