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

Understanding the gravity of a red flag warning and adhering to these precautions is pivotal in mitigating the risk of wildfires during these perilous conditions. —Ca Weather Bot, Sacbee.com, 28 July 2025

A lot of those stars host shows of their own (more on Stewart in a moment), and while Colbert joked about his show's finances, late-night shows are in a perilous financial position — and CBS killing off Colbert's show gives other networks an opening to do the same. —Bill Goodykoontz, AZCentral.com, 22 July 2025

In a perilous moment, the titular character uses the bullwhip to attach to a German cargo truck’s rear and drag behind it, saving himself from getting crushed beneath it. —India Brown, Robb Report, 22 July 2025

Though the top of the surface is within reach, things become perilous when a woman comes tumbling over the side of the mass, nearly taking down the men with her. —Aramide Tinubu, Variety, 17 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