RU'IN, noun [Latin ruo, to fall, to rush down.]

1. Destruction; fall; overthrow; defeat; that change of any thing which destroys it, or entirely defeats its object, or unfits it for use; as the ruin of a house; the ruin of a ship or an army; the ruin of a constitution of government; the ruin of health; the ruin of commerce; the ruin of public or private happiness; the ruin of a project.

2. Mischief; bane; that which destroys.

The errors of young men are the ruin of business.

3. ruin more generally ruins, the remains of a decayed or demolished city, house, fortress, or any work of art or other thing; as the ruins of Balbec, Palmyra or Persepolis; the ruins of a wall; a castle in ruins.

The labor of a day will not build up a virtuous habit on the ruins of an old and vicious character.

4. The decayed or enfeebled remains of a natural object; as, the venerable old man presents a great mind in ruins.

5. The cause of destruction.

They were the ruin of him and of all Israel. 2 Chronicles 28:23.

RU'IN, v, t,

1. To demolish; to pull down, burn, or otherwise destroy; as, to ruin a city or an edifice.

2. To subvert; to destroy; as, to ruin a state or government.

3. To destroy; to bring to an end; as, to ruin commerce or manufactures.

4. To destroy in any manner; as, to ruin health or happiness; to ruin reputation.

5. To counteract; to defeat; as, to ruin a plan or project.

6. To deprive of felicity or fortune.

By thee rais'd I ruin all my foes.

Grace with a nod, and ruin with a frown.

7. To impoverish; as, to be ruined by speculation.

The eyes of other people are the eyes that ruin us.

8. To bring to everlasting misery; as, to ruin the soul.

RU'IN, verb intransitive

1. To fall into ruins.

2. To run to ruin; to fall into decay or be dilapidated.

Though he his house of polish'd marble build, yet shall it ruin like the moth's frail cell.

3. To be reduced; to be brought to poverty or misery.

If we are idle, and disturb the industrious in their business, we shall ruin the faster.

[Note. This intransitive use of the verb is now unusual.]