Ruinous

Webster's Dictionary of the English Language

·adj Composed of, or consisting in, ruins.

II. Ruinous ·adj Causing, or tending to cause, ruin; destructive; baneful; pernicious; as, a ruinous project.

III. Ruinous ·adj Characterized by ruin; ruined; dilapidated; as, an edifice, bridge, or wall in a ruinous state.