D defs.my
Entry 3 senses Webster, 1913

Ruinous

/ro͞o'-ən-əs/ · Ru·in·ous · IPA /ˈɹuː.ɪnəs/
01 a. Causing, or tending to cause, ruin; destructive; baneful; pernicious; as, a ruinous project.
  1. 1.
    Causing, or tending to cause, ruin; destructive; baneful; pernicious; as, a ruinous project.
    “After a night of storm so ruinous.” Milton.
  2. 2.
    Characterized by ruin; ruined; dilapidated; as, an edifice, bridge, or wall in a ruinous state.
  3. 3.
    Composed of, or consisting in, ruins.
    “Behold, Damascus . . . shall be a ruinous heap.” — Isa. xvii. 1.