bringing or tending to bring ruin; destructive; disastrous: a ruinous war.
fallen into ruin; dilapidated: a ruinous house.
consisting of ruins: a ruinous city from antiquity.

Origin of ruinous

1350–1400; Middle English ruynouse < Latin ruīnōsus, equivalent to ruīn(a) ruin + -ōsus -ous
Related formsru·in·ous·ly, adverbru·in·ous·ness, nounnon·ru·in·ous, adjectivenon·ru·in·ous·ly, adverbnon·ru·in·ous·ness, nounun·ru·in·ous, adjectiveun·ru·in·ous·ly, adverbun·ru·in·ous·ness, noun

Synonyms for ruinous Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for ruinous

Contemporary Examples of ruinous

Historical Examples of ruinous

  • This was effected, and the ruinous city was in the hands of the French.

  • But the aims of states should be good, or else, like the prayer of Theseus, they may be ruinous to themselves.



  • Truly it is not a ruinous service, Socrates (he answered)—far from it.

  • Nothing is so ruinous; and just at the moment when you want them, they will not be forthcoming.

  • This series was published in 1735, and the church was then in a ruinous condition.

    Hampstead and Marylebone

    Geraldine Edith Mitton

British Dictionary definitions for ruinous



causing, tending to cause, or characterized by ruin or destructiona ruinous course of action
Derived Formsruinously, adverbruinousness, noun
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for ruinous

late 14c., "going to ruin," from Old French ruinos (Modern French ruineux) or directly from Latin ruinosus "tumbling down, going to ruin," from ruina (see ruin (n.)). Meaning "causing ruin" is from mid-15c. Related: Ruinously.

Online Etymology Dictionary, © 2010 Douglas Harper