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.

PERILOUS definition: involving or full of grave risk or peril; hazardous; dangerous. See examples of perilous used in a sentence.

/ ˈper·ə·ləs / Add to word list dangerous (Definition of perilous from the Cambridge Academic Content Dictionary © Cambridge University Press)

(ˈperələs) adjective involving or full of grave risk or peril; hazardous; dangerous a perilous voyage across the Atlantic in a small boat

Definition of perilous adjective in Oxford Advanced Learner's Dictionary. Meaning, pronunciation, picture, example sentences, grammar, usage notes, synonyms and more.

Define perilous. perilous synonyms, perilous pronunciation, perilous translation, English dictionary definition of perilous. adj. Full of or involving peril; dangerous or risky. per′il·ous·ly adv. …

WordReference Random House Unabridged Dictionary of American English © 2025 per•il•ous (per′ ə ləs), adj. involving or full of grave risk or peril; hazardous; dangerous: a perilous voyage across the …

Feb 2, 2026 · Adjective perilous (comparative more perilous, superlative most perilous) Dangerous, full of peril.

Perilous definition: Full of or involving peril; dangerous or risky.

Definition of perilous Extremely dangerous, fraught with risks, or characterized by the potential for harm, injury, or adverse outcomes. "The climb was perilous and required extreme caution."