ruinous

adjective

ru·​in·​ous ˈrü-ə-nəs 

1

: dilapidated, ruined

2

: causing or tending to cause ruin

ruinously adverb

ruinousness noun

Synonyms of ruinous

• disastrous
• fatal
• unfortunate
• catastrophic

Examples of ruinous in a Sentence

The house has fallen into a ruinous state.

a ruinous miscalculation of the financial markets left them bankrupt

Recent Examples on the Web

These people are ridiculous; these people are ruinous. — Eugenie Brinkema, ARTnews.com, 14 June 2026

Distracting people from a ruinous war and domestic unrest with bread and circuses isn’t new. — Sun Sentinel Editorial Board, Sun Sentinel, 17 June 2026

Instead, gum arabic, like so much of the country’s gargantuan wealth, now provides both the reason and resources for its staggeringly ruinous civil war. — Nabih Bulos, Los Angeles Times, 31 May 2026

The controversial relationship likely proved ruinous for Gates’ relationship with his now ex wife. — Victor Tangermann, Futurism, 11 June 2026

Word History

First Known Use

14th century, in the meaning defined at sense 1

Kids Definition

ruinous

adjective

ru·​in·​ous ˈrü-ə-nəs 

: causing or tending to cause ruin : destructive

ruinously adverb