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

Catching Astoria to relocate her has proved impossible so far — during her brief tenure uptown, NYPD officers repeatedly failed to nab her, leading her to wander into perilous traffic. —Scottie Andrew, CNN Money, 23 Nov. 2025

Johnson is equipped to meet this perilous moment. —David Canfield, HollywoodReporter, 21 Nov. 2025

In the game, players must work together, chained to one another, to climb, survive, and escape perilous environments. —Andreas Wiseman, Deadline, 19 Nov. 2025

Understanding the gravity of a red flag warning and adhering to these precautions is paramount in averting wildfires during these perilous conditions. —Nc Weather Bot, Charlotte Observer, 16 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