merciless

adjective

mer·​ci·​less ˈmər-si-ləs How to pronounce merciless (audio)
Synonyms of mercilessnext
: having or showing no mercy : pitiless
the merciless killing of innocent people
mercilessly adverb
mercilessness noun

Synonyms

See All Synonyms & Antonyms in Thesaurus

Examples of merciless in a Sentence

the merciless killing of innocent people He has been merciless in his criticism of his opponent.
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.
In Season 4 of the Max comedy (streaming weekly on Thursdays), Deborah (Jean Smart) is struggling to find her ground amid a merciless feud with head writer Ava (Hannah Einbinder). — Erin Jensen, USA Today, 3 May 2025 The math of those slices off the point totals was merciless: Should a big prep draw a field of less than five, a 50-point second place was reduced to a 25-point place showing, which can mean the difference between getting a stall in the Churchill gate and not getting to race. — Guy Martin, Forbes.com, 30 Apr. 2025 Like the rest of Perry’s recent output, the online antics surrounding the Lifetimes Tour have been merciless — with social media making fun of her choreography and sets and accusing her of using AI. — Jason P. Frank, Vulture, 25 Apr. 2025 Inspired by Lauren’s late mother, Adele, who was diagnosed with early-onset Alzheimer’s at the age of 55, their family knows that this merciless disease is no laughing matter. — Jeff Conway, Forbes.com, 17 Apr. 2025 See All Example Sentences for merciless

Word History

First Known Use

14th century, in the meaning defined above

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

Rhymes for merciless

See All Rhymes for merciless

Browse Nearby Words

mercifully
merciless
mercuhydrin
See all Nearby Words

Cite this Entry

“Merciless.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/merciless. Accessed 12 May. 2025.

Copy Citation

Share

Kids Definition

merciless

adjective
mer·​ci·​less ˈmər-si-ləs How to pronounce merciless (audio)
: having no mercy : pitiless
merciless slaughter
mercilessly adverb
mercilessness noun

More from Merriam-Webster on merciless

Nglish: Translation of merciless for Spanish Speakers

Last Updated: - Updated example sentences
Love words? Need even more definitions?

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

Popular in Grammar & Usage

See More

'Affect' vs. 'Effect'

Words You Always Have to Look Up

How to Use Em Dashes (—), En Dashes (–) , and Hyphens (-)

Democracy or Republic: What's the difference?

Every Letter Is Silent, Sometimes: A-Z List of Examples
See More

Popular in Wordplay

See More

Flower Etymologies For Your Spring Garden

Great Big List of Beautiful and Useless Words, Vol. 1

Rare and Amusing Insults, Volume 3

'Za' and 9 Other Words to Help You Win at SCRABBLE

8 Words for Lesser-Known Musical Instruments
See More

Popular

See More

'Affect' vs. 'Effect'

Flower Etymologies For Your Spring Garden

Great Big List of Beautiful and Useless Words, Vol. 1
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 Word Game 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?
Missing Letter A daily crossword with a twist
crayons-in-a-circle
Guess the Color Quiz Questions that use the whole box of crayons.
See All