ruin

Concise Oxford English Dictionary © 2008 Oxford University Press:
ruin/ˈruːɪn/

▶noun

• 1 physical destruction or collapse.

• 2 the remains of a building that has suffered much damage.

• 3 a dramatic decline; a downfall.

▶verb

• 1 damage irreparably; reduce to a state of ruin.

  ■ reduce to poverty or bankruptcy.

• 2 literary fall headlong.

– phrases
in ruins in a state of complete collapse.

– origin ME: from OFr. ruine, from L. ruina, from ruere ‘to fall’.