the physical destruction or disintegration of something or the state of disintegrating or being destroyed

a large white house falling into gentle ruin

the remains of a building, typically an old one that has suffered much damage or disintegration

the ruins of the castle

the church is a ruin now

reduce (a building or place) to a state of decay, collapse, or disintegration

the castle was ruined when dynamite was used to demolish one of the corner towers

fall headlong or with a crash

carriages go ruining over the brink from time to time