perilous

adjective

per·​il·​ous ˈper-ə-ləs 

ˈpe-rə-

: full of or involving peril

a perilous journey

perilously adverb

perilousness noun

Synonyms of perilous

• 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

The following list of darkly gripping movies include undercover police operations, addictive assassin dramas, and perilous hijacking odysseys based on true stories. —Griff Griffin, MSNBC Newsweek, 6 Dec. 2025

When Amir is arrested on charges of attempting to create social unrest, Fatima embarks on a perilous journey with an old cathode-ray tube television and DVD player loaded onto a yak, determined to screen the film in remote villages. —Naman Ramachandran, Variety, 1 Dec. 2025

All week, Banjo preached to his coverage unit about the Falcons’ punt returner, Jamal Agnew, who had a propensity for fielding punts no matter how perilous his surroundings. —Zack Rosenblatt, New York Times, 1 Dec. 2025

The guy who went into the Vikings’ preseason finale against Tennessee’s starters in August and, surrounded by a bunch of reserves, led a functioning offense, consistently ripping on-time, on-target passes in the face of perilous pressure. —Jace Frederick, Twin Cities, 29 Nov. 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