perilous

1 of 2

adjective

per·​il·​ous ˈper-ə-ləs How to pronounce perilous (audio)
ˈpe-rə-
Synonyms of perilous
: full of or involving peril
a perilous journey
perilously adverb
perilousness noun

perilousness

2 of 2

noun

per·​il·​ous·​ness
plural -es
: the quality or state of being perilous

Synonyms of perilous

Relevance

Adjective

See All Synonyms & Antonyms in Thesaurus
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

Adjective a perilous journey across the mountains a perilous journey through hostile territory
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Adjective
One soldier waited two days for help and could not walk; the drone’s flight to safety took less than 15 minutes, illustrating its potential to replace perilous ground rescues. — Derek Gatopoulos, Los Angeles Times, 27 Oct. 2026 The truckers that have managed to ferry water into Taiz have in some cases tripled their rates to make the perilous journey. — ABC News, 24 Oct. 2026 Polyphemus prays to his father Poseidon to curse Odysseus, dooming him on a long and perilous journey. — Jazz Tangcay, Variety, 22 Oct. 2026 Advertisement The convergence of these calculations makes the coming weeks particularly perilous. — Ali Vaez, Time, 21 Oct. 2026 See All Example Sentences for perilous

Word History

Etymology

Adjective

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

Adjective

14th century, in the meaning defined above

Time Traveler
The first known use of perilous was in the 14th century

Rhymes for perilous

See All Rhymes for perilous

Browse Nearby Words

perilless
perilous
perilously
See all Nearby Words

Cite this Entry

“Perilous.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/perilous. Accessed 30 Oct. 2026.

Copy Citation

Kids Definition

perilous

adjective
per·​il·​ous ˈper-ə-ləs How to pronounce perilous (audio)
: full of or involving peril
perilously adverb
perilousness noun
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

Last Updated: - Updated example sentences

More from Merriam-Webster

Word of the Day

Listen to the pronunciation of reticent

See Definitions and Examples »

Popular in Grammar & Usage

See More

How to Use 'Who' vs. 'Whom'

Merriam-Webster’s Great Big List of Words You Love to Hate

'Affect' vs. 'Effect'

'A' or 'an'? What about before 'h'? An Indefinite Article Guide

Why is '-ed' sometimes pronounced at the end of a word?
See More

Popular in Wordplay

See More

The Longest Long Words List

9 Words That Sound Like Insults But Aren't

Pwn, Skibidi, Girlboss and Other Words Added to the 2026 Scrabble Dictionary

The Words of the Week - Oct. 30

12 Lovely and Unusual Words for the Natural World
See More

Popular

See More

How to Use 'Who' vs. 'Whom'

The Longest Long Words List

9 Words That Sound Like Insults But Aren't
See More

Games & Quizzes

See All
Play Quordle: Guess all four words in a limited number of tries. Each of your guesses must be a real 5-letter word.
Quordle Can you solve 4 words at once?
Play Blossom: Solve today's spelling word game by finding as many words as you can using just 7 letters. Longer words score more points.
Blossom Pick the best words!
Play Missing Letter: a crossword with a twist. Each of the 25 puzzle words start with a different letter of the alphabet. Which letter is missing?
The Missing Letter A daily crossword with a twist
different halloween monsters in silhouette
A Monstrous Vocab Quiz Words That Go Bump in the Night
See All