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Synonyms

perilous

American  
[per-uh-luhs] / ˈpɛr ə ləs /

adjective

  1. involving or full of grave risk or peril; hazardous; dangerous.

    a perilous voyage across the Atlantic in a small boat.
    Synonyms:
    risky
    Antonyms:
    safe
perilous British  
/ ˈpɛrɪləs /

adjective

  1. very hazardous or dangerous

    a perilous journey
"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

Other Word Forms

  • nonperilous adjective
  • perilously adverb
  • perilousness noun
  • unperilous adjective

Etymology

Origin of perilous

First recorded in 1250–1300; Middle English, from Anglo-French perillous, from Latin perīculōsus; peril, -ous

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 said, relying on a future inheritance is a perilous strategy for compensation.

From MarketWatch • Mar. 30, 2026

The previous year he'd made the perilous journey to escape from North to South Korea, using an international underground network of safe houses and brokers.

From BBC • Mar. 27, 2026

But it could have added another element of urgency as perilous fire weather was beginning to overwhelm the region.

From Los Angeles Times • Mar. 24, 2026

"The war in the Middle East has reached a perilous stage" with the strikes on Natanz and Dimona, WHO chief Tedros Adhanom Ghebreyesus said on X.

From Barron's • Mar. 22, 2026

Shinnying out onto a perilous but hidden spot, he gripped the roof with one hand and his stopwatch with the other.

From "Seabiscuit: An American Legend" by Laura Hillenbrand

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.