Ru'in-oūs, a.

a. [Lat. ruinosus, It. ruinoso, rovinoso, Sp. & Pg. ruinoso, Pr. ruynos, Fr. ruineux. See RUIN.]

1. Destructive; baneful; pernicious; bringing, or tending to bring, certain ruin. “After a night of storm so ruinous.” Milton.
2. Characterized by ruin; as, an edifice, bridge, or wall in a ruinous state.
3. Composed of, or consisting in, ruins. Behold, Damascus . . . shall be a ruinous heap. Is. xvii. 1.

SYN.—Dilapidated; decayed; demolished; pernicious; destructive; baneful; wasteful; injurious; mischievous.