Dictionary.com
Thesaurus.com
Synonyms

relentless

American  
[ri-lent-lis] / rɪˈlɛnt lɪs /

adjective

  1. not easing or slackening; maintaining speed, vigor, etc..

    a relentless barrage of bad news.

  2. unyieldingly severe, strict, or harsh.

    a relentless crackdown on human rights.

    Synonyms:
    unyielding, adamant, obdurate, unbending, rigid
    Antonyms:
    merciful

relentless British  
/ rɪˈlɛntlɪs /

adjective

  1. (of an enemy, hostile attitude, etc) implacable; inflexible; inexorable

  2. (of pace or intensity) sustained; unremitting

"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

Related Words

See inflexible.

Other Word Forms

  • relentlessly adverb
  • relentlessness noun

Etymology

Origin of relentless

First recorded in 1585–95; relent + -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 combination of his relentless service game and feathery drop shots made Djokovic feel every day of their 16-year age gap.

From The Wall Street Journal

But an indefatigable Volkanovski's agility and relentless striking eventually wore down his flagging challenger, who was unable to land a knockout in the final round.

From Barron's

Djokovic is not afraid to go toe to toe with hostile fans, using their jibes to fuel his relentless quest for glory and showing the depth of his competitiveness.

From Barron's

Friends describe Lemon as relentless, channeling every attempt to hold him back into motivation to push harder.

From Los Angeles Times

But the schedule has been particularly relentless as Newcastle fight on four fronts this season, so Woltemade and Wissa have had to rely on individual video analysis sessions.

From BBC