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 paramount in averting wildfires during these perilous conditions. —Ca Weather Bot, Sacbee.com, 4 July 2025

The rap scene, then steeped in gangster culture, was perilous. —Janine Rubenstein, People.com, 3 July 2025

The book comes August 5 from Blackstone Publishing and The Story Factory, timed to the 80th anniversary of the moment the world entered the perilous nuclear age. —Mike Fleming Jr, Deadline, 27 June 2025

For decades, migrants driven by war and poverty have made perilous crossings to reach Europe’s southern borders, with thousands estimated to die every year in their bid to reach a continent grown increasingly hostile to migration. —CNN Money, 26 June 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