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merciless

American  
[mur-si-lis] / ˈmɜr sɪ lɪs /

adjective

  1. without mercy; having or showing no mercy; pitiless; cruel.

    a merciless critic.
    Synonyms:
    inexorable, unsympathetic, fell, unrelenting, relentless, hard
    Antonyms:
    compassionate
merciless British  
/ ˈmɜːsɪlɪs /

adjective

  1. without mercy; pitiless, cruel, or heartless

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Word Forms

  • mercilessly adverb
  • mercilessness noun

Etymology

Origin of merciless

First recorded in 1300–50; Middle English mercyles; mercy, -less

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

The snakes hissed with laughter, their eyes flashing with merciless glee.

From Literature

“He can be merciless in getting his objectives in negotiations,” Mora said.

From The Wall Street Journal

He had been in Britain since 208, overseeing a series of merciless campaigns into present-day Scotland.

From The Wall Street Journal

Cruel faces leered at him with merciless white eyes.

From Literature

Contemporaries regarded this merciless battle as “a second Agincourt,” akin to Henry V’s victory, against the odds, in 1415.

From The Wall Street Journal

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.