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

Large rock-face murals scattered across the desert in northern Saudi Arabia represent one of the most ambitious – and perilous – creative feats of ancient humans, with researchers arguing that the massive carvings acted as visual beacons, guiding people toward crucial water sources. —New Atlas, 30 Sep. 2025

This context and backdrop adorns the film with considerable energy, various colorful personalities and smartly edited archival news footage that deepens our understanding of the perilous stakes. —Tomris Laffly, Variety, 28 Sep. 2025

My hope was that exploring the past in a nuanced way might offer insight into our surprising and perilous present. —Cressida Leyshon, New Yorker, 28 Sep. 2025

The second is practically perilous, since a shutdown is guaranteed to hurt the economy — a dynamic Democrats have invoked over a long history of battling with Republicans to keep the government open. —Al Weaver, The Hill, 27 Sep. 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