relentless

adjective

re·​lent·​less ri-ˈlent-ləs 

: showing or promising no abatement of severity, intensity, strength, or pace : unrelenting

relentless pressure

a relentless campaign

relentlessly adverb

relentlessness noun

Synonyms of relentless

• grim
• determined
• persistent
• unrelenting
• ruthless

Examples of relentless in a Sentence

Her relentless optimism held the team together.

The hunter was relentless in pursuit of his prey.

a relentless opponent of deregulation

Recent Examples on the Web

This not-quite-title song, which is nearly eight minutes long, is a sort of mini-suite, opening with a dog barking, giving way to an acoustic-guitar melody accompanying polyphonic vocals, then becoming electric and crashingly alive, until the relentless screech of a guitar drags you to the end. —Hanif Abdurraqib, New Yorker, 18 Dec. 2025

Zane Lowe has made a career out of relentless positivity. —Spencer Kornhaber, The Atlantic, 18 Dec. 2025

Growing up in Dayton, Ohio, the brothers had developed deep mechanical instincts, nurtured through their bicycle business and relentless study of earlier glider experiments by pioneers like Otto Lilienthal. —Kaif Shaikh, Interesting Engineering, 17 Dec. 2025

None of this will stop our relentless pursuit of Making America Great Again! —Greta Bjornson, PEOPLE, 16 Dec. 2025

Word History

First Known Use

1592, in the meaning defined above

Kids Definition

relentless

adjective

re·​lent·​less ri-ˈlent-ləs 

: not lessening in severity, intensity, strength, or pace : unrelenting

relentless criticism

relentlessly adverb

relentlessness noun