Ru"in, v. t. [imp. & p. p. Ruined (?);p. pr. & vb. n. Ruining.] [Cf. F. ruiner, LL. ruinare. See Ruin, 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.

this mortal house I'll ruin.

By thee raised, I ruin all my foes.

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

By the fireside there are old men seated,
Seeling ruined cities in the ashes.

Ru"in, v. i. To fall to ruins; to go to ruin; to become decayed or dilapidated; to perish. [R.]

Though he his house of polished marble build,
Yet shall it ruin like the moth's frail cell.

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

Ru"in (?), n. [OE. ruine, F. ruine, fr. L. ruina, fr. ruere, rutum, to fall with violence, to rush or tumble down.] 1. The act of falling or tumbling down; fall. [Obs.] "His ruin startled the other steeds." Chapman.

2. 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. "Ruin seize thee, ruthless king!" Gray.

3. 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.

The Veian and the Gabian towers shall fall,
And one promiscuous ruin cover all;
Nor, after length of years, a stone betray
The place where once the very ruins lay.

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

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

5. That which promotes injury, decay, or destruction.

The errors of young men are the ruin of business.

Syn. -- Destruction; downfall; perdition; fall; overthrow; subversion; defeat; bane; pest; mischief.