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

Top congressional Democrats on military, intelligence and foreign policy matters on Tuesday accused President Trump and Elon Musk of gravely undermining national security by aligning with President Vladimir V. Putin of Russia and dismantling the federal security work force at a perilous time. —Carl Hulse, New York Times, 5 Mar. 2025

Our ancestors crossed a vast ocean, strode into the unknown wilderness, and carved their fortunes from the rock and soil of a perilous and very dangerous frontier. —CBS News, 5 Mar. 2025

Our ancestors crossed a vast ocean, strode into the unknown wilderness, and carve their fortunes from the rock and soil of a perilous and very dangerous frontier. —Time Staff, TIME, 5 Mar. 2025

Even with Republican majorities, shutting down an entire federal department is politically perilous—especially one that touches every state and school district. —Shahar Ziv, Forbes, 4 Mar. 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