ruinous
Americanadjective
-
bringing or tending to bring ruin; destructive; disastrous.
a ruinous war.
- Synonyms:
- catastrophic, devastating, calamitous
-
fallen into ruin; dilapidated.
a ruinous house.
-
consisting of ruins.
a ruinous city from antiquity.
adjective
Other Word Forms
- nonruinous adjective
- nonruinously adverb
- nonruinousness noun
- ruinously adverb
- ruinousness noun
- unruinous adjective
- unruinously adverb
- unruinousness noun
Etymology
Origin of ruinous
1350–1400; Middle English ruynouse < Latin ruīnōsus, equivalent to ruīn ( a ) ruin + -ōsus -ous
Explanation
Something ruinous is really terrible or devastating, like a ruinous hurricane that floods your house or the ruinous effect of a new law on a country's poorest citizens. The adjective ruinous perfectly describes something so bad that it truly causes ruin, "the destruction or disintegration of something." A house fire can be ruinous, and so can a bad hand at a poker table, if the player has bet her last dollar. Ruinous and ruin comes from the Latin root ruina, "a collapse, a rushing down, a tumbling down."
Vocabulary lists containing ruinous
Hamilton
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30 GRE Words Beginning with "Q" "R" and "S"
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Dubliners
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
That’s how fast it is supposed to be able to grow without stoking ruinous inflation.
From MarketWatch • Feb. 20, 2026
Ye ran through the ruinous effects of his injury and subsequent diagnosis, saying it caused him to avoid seeking the help he needed.
From Salon • Jan. 26, 2026
“It’s been years that we’ve been warning management about the ruinous state of equipment and lack of adequate staffing.”
From The Wall Street Journal • Dec. 15, 2025
Starting over elsewhere becomes a financially ruinous proposition.
From Slate • Nov. 4, 2025
Then among the greater casts there fell another hail, less ruinous but more horrible.
From "The Return of the King" by J.R.R. Tolkien
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
