IPA: /ˈruːɪn/
KK: /ruɪn/
To fall into a state of destruction or disrepair.
The old castle began to ruin after years of neglect.
Past: ruined
Past Participle: ruined
A state of complete destruction or the remains of something that has been destroyed, often referring to buildings or structures that are no longer intact.
The ancient ruins of the castle attracted many tourists.
To cause something to be destroyed or to be in a state of disrepair, often beyond repair.
The heavy rain could ruin the picnic plans we made for Saturday.
Past: ruined
Past Participle: ruined
Ruin comes from the Latin 'ruina' (meaning a fall or collapse), which is derived from 'ruere' (meaning to fall or rush down). The word 'ruin' refers to the state of being fallen down or destroyed.
Think of a 'fall' ('ruere') that leads to destruction — that's why ruin means to be in a state of collapse.