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.

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

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

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. …

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

There are five meanings listed in OED's entry for the word perilous, one of which is labelled obsolete. See ‘Meaning & use’ for definitions, usage, and quotation evidence.

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 …

Dec 14, 2025 · perilous (comparative more perilous, superlative most perilous) Dangerous, full of peril. quotations

Definition of perilous. English dictionary and integrated thesaurus for learners, writers, teachers, and students with advanced, intermediate, and beginner levels.