1. (n.) The act of falling or tumbling down; fall.

2. (n.) Such a change of anything as destroys it, or entirely defeats its object, or unfits it for use; destruction; overthrow; as, the ruin of a ship or an army; the ruin of a constitution or a government; the ruin of health or hopes.

3. (n.) That which is fallen down and become worthless from injury or decay; as, his mind is a ruin; especially, in the plural, the remains of a destroyed, dilapidated, or desolate house, fortress, city, or the like.

4. (n.) The state of being decayed, or of having become ruined or worthless; as, to be in ruins; to go to ruin.

5. (n.) That which promotes injury, decay, or destruction.

6. (n.) To bring to ruin; to cause to fall to pieces and decay; to make to perish; to bring to destruction; to bring to poverty or bankruptcy; to impair seriously; to damage essentially; to overthrow.

7. (v. i.) To fall to ruins; to go to ruin; to become decayed or dilapidated; to perish.