Webster's Revised Unabridged Dictionary · 1913

Ruin

Ruin , noun

[Old English ruine, French ruine, from Latin ruina, from ruere, rutum, to fall with violence, to rush or tumble down.]

1.
The act of falling or tumbling down; fall. [Obsolete]
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. — Addison
The labor of a day will not build up a virtuous habit on the ruins of an old and vicious character. — Buckminster
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. — Bacon

Ruin , transitive verb

[Compare French ruiner, Late Latin 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. — Shakespeare
By thee raised, I ruin all my foes. — Milton
The eyes of other people are the eyes that ruin us. — Franklin
By the fireside there are old men seated, Seeling ruined cities in the ashes. — Longfellow

Ruin , intransitive verb

To fall to ruins; to go to ruin; to become decayed or dilapidated; to perish. [Rare]
Though he his house of polished marble build, Yet shall it ruin like the moth's frail cell. — Sandys
If we are idle, and disturb the industrious in their business, we shall ruin the faster. — Locke