perilous

adjective

per·​il·​ous ˈper-ə-ləs 

ˈpe-rə-

: full of or involving peril

a perilous journey

perilously adverb

perilousness noun

Synonyms

• dangerous
• grave
• grievous
• hazardous
• jeopardizing
• menacing
• parlous
• risky
• serious
• threatening
• unhealthy
• unsafe
• venturesome

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 original film tells the story of a perilous trip undertaken by Hikari 109, a high-speed, first-generation bullet train traveling from Tokyo to Hakata. —Kayti Burt, Time, 23 Apr. 2025

Albi opened in early 2020, a perilous time for any new business to kick off. —Melissa Kravitz Hoeffner, Forbes.com, 21 Apr. 2025

Living in a Radius For many unauthorized immigrants who are not detained at the border, the perilous journey to the United States ends inside Geo Group’s surveillance system. —Paul Mozur, New York Times, 14 Apr. 2025

Listen to this article Starting a new theater company during this perilous time for arts funding takes guts, imagination and talent. —Pam Kragen, San Diego Union-Tribune, 8 Apr. 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