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

These currents vary in speed and can swiftly become perilous for anyone venturing into the surf. —Nc Weather Bot, Charlotte Observer, 11 Oct. 2025

The Bleed Black will tell the story of a family’s perilous journey west to save their son a decade after colossal monsters began ravaging American cities. —Jesse Whittock, Deadline, 10 Oct. 2025

My favorite elements of the Shackleton story involve the camaraderie of the sailors, the perilous journey of the James Caird, and, yeah, all of the seal hunting. —Frederick Dreier, Outside, 7 Oct. 2025

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

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