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

The mullahs allowed the ruinous Iran-Iraq war to go on for years, leaving hundreds of thousands dead. —ABC News, 8 Apr. 2026

Their efforts soon bore strange and ruinous fruit. —Caroline Fraser, The New York Review of Books, 4 Apr. 2026

Wrinkles, sun spots and sagging skin have become so demonized, that even teenagers — decades away from this reality — and increasingly men, previously exempt from this ruinous beauty standard, have started to fear, anticipate and prepare for their arrival. —Leah Dolan, CNN Money, 2 Apr. 2026

Slowly, Castro’s cronies built a kleptocracy that proved ruinous to the Cuban people, but hugely profitable to them. —Quico Toro, The Atlantic, 27 Mar. 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