perilous

adjective

per·​il·​ous ˈper-ə-ləs 

ˈpe-rə-

: full of or involving peril

a perilous journey

perilously adverb

perilousness noun

Synonyms

• dangerous
• hazardous
• risky
• serious

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

Murphy only wants to escape and regain custody of his daughter, Penny, but becomes entangled in Clancy’s perilous gold smuggling scheme, facing threats from both the treacherous wilderness and potential betrayal within his own group. —Leo Barraclough, Variety, 6 Aug. 2025

The lack of comprehensive protections and support systems for athletes echoes the Wild West’s perilous landscape, where pioneers often had to fend for themselves amid uncertainty and danger. —Jim Martin, Denver Post, 3 Aug. 2025

Thrust into a high-stakes game of cat and mouse with a Coast Guard officer (James) in hot pursuit, the commander must outmaneuver blockades and navigate perilous threats both inside and outside the submarine. —Borys Kit, HollywoodReporter, 30 July 2025

On top of all that, women are looking for romance at a time when the U.S. government is stripping away their reproductive rights, making pregnancy more perilous, and dismantling protections against gender discrimination. —Faith Hill, The Atlantic, 30 July 2025

Word History

Etymology

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

Rhymes for perilous

• carolus
• garrulous
• querulous
• puberulous

Kids Definition

perilous

adjective

per·​il·​ous ˈper-ə-ləs 

: full of or involving peril

perilously adverb

perilousness noun