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

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.
Against some audiences’ will, Ari Aster’s merciless black comedy drags us back to May 2020 when tempers, temperatures and misinformation were heating up across America. Amy Nicholson, Los Angeles Times, 10 Mar. 2026 The group is preyed upon by not only the harsh terrain, beset by hunger and desperation, but are also stalked by something older and far more merciless than the desert itself. Thinus Ferreira, Variety, 6 Mar. 2026 With no hope of rescue, a father (Pine) and his daughter (Bell) must fight to survive against a merciless predator that blends in with the snow. Matt Grobar, Deadline, 6 Mar. 2026 Waltz lends a slimy charisma to the merciless SS colonel, who gets a satisfying comeuppance via carving knife. Brian Truitt, USA Today, 4 Mar. 2026 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

Browse Nearby Words

Cite this Entry

“Merciless.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/merciless. Accessed 14 Mar. 2026.

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

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!

More from Merriam-Webster