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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.

Doing so would make wartime changes in the strait permanent, inject a new price premium into oil markets and push the shipping industry down a perilous path.

From The Wall Street Journal • Apr. 1, 2026

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

From MarketWatch • Mar. 30, 2026

The World Health Organisation said that the conflict was at a "perilous stage" and called for restraint.

From BBC • Mar. 24, 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

“Yes. It does. But that should not be new information to you. This task is a perilous one,” Guardian responds quickly.

From "A Rover's Story" by Jasmine Warga

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.