per·​il·​ous ˈper-ə-ləs How to pronounce perilous (audio)
: full of or involving peril
a perilous journey
perilously adverb
perilousness noun
Choose the Right Synonym for perilous

dangerous, hazardous, precarious, perilous, risky mean bringing or involving the chance of loss or injury.

dangerous applies to something that may cause harm or loss unless dealt with carefully.

soldiers on a dangerous mission

hazardous implies great and continuous risk of harm or failure.

claims that smoking is hazardous to your health

precarious suggests both insecurity and uncertainty.

earned a precarious living by gambling

perilous strongly implies the immediacy of danger.

perilous mountain roads

risky often applies to a known and accepted danger.

shied away from risky investments

Examples of perilous in a Sentence

a perilous journey across the mountains a perilous journey through hostile territory
Recent Examples on the Web Climate & Environment California mountain lion population is thousands fewer than previously estimated Jan. 7, 2024 Griffith Park, surrounded on all sides by perilous freeways and roads, isn’t an easy place for a lion to get to — or leave. Lila Seidman, Los Angeles Times, 11 June 2024 Here’s the setup: Following the events of the Survivor series, Lara Croft has abandoned her friends to embark on increasingly more perilous solo adventures. Andrew Webster, The Verge, 1 June 2024 However, a downturn in beer sales across the country — a more-than 3 percent drop in volume in 2022 alone, according to the trade group, the Brewers Association — landed it in a perilous position in recent years. John Metcalfe, The Mercury News, 31 May 2024 Two presidential debates have been announced — without the involvement of the Commission on Presidential Debates (CPD) — putting the CPD in a rare and potentially perilous void of irrelevance. Major Garrett, CBS News, 31 May 2024 See all Example Sentences for perilous 

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'perilous.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


Middle English perilous, perelous, borrowed from Anglo-French perilleus, perillous, going back to Latin perīculōsus, from perīculum "test, risk, peril entry 1" + -ōsus -ous

First Known Use

14th century, in the meaning defined above

Time Traveler
The first known use of perilous was in the 14th century

Dictionary Entries Near perilous

Cite this Entry

“Perilous.” Dictionary, Merriam-Webster, Accessed 19 Jun. 2024.

Kids Definition


per·​il·​ous ˈper-ə-ləs How to pronounce perilous (audio)
: full of or involving peril
perilously adverb
perilousness noun

More from Merriam-Webster on perilous

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!