ruinous definition by Webster's New World
- falling or fallen into ruin; dilapidated; decayed
- bringing or tending to bring ruin; very destructive or harmful; disastrous: ruinous floods
Origin: Middle English ruinouse ; from Classical Latin ruinosus
ruinous definition by American Heritage Dictionary
- Causing or apt to cause ruin; destructive.
- Falling to ruin; dilapidated or decayed.
- ruˈin·ous·ly adverb
- ruˈin·ous·ness noun