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

But there is little sympathy coming out of Ukraine, where civilian infrastructure, including businesses, have endured years of relentless Russian attacks. — Daniela Suarez, NBC news, 5 Aug. 2026

Ted was genuinely out of his depth, the conflicts felt earned, and the show still had to persuade audiences that its relentless optimism wasn’t naïve. — Nicholas Quah, Vulture, 5 Aug. 2026

The mogul has only become a greater cultural lightning rod since then with a relentless series of social media trolls and the platforming of numerous conspiracy theories. — Steven Zeitchik, HollywoodReporter, 5 Aug. 2026

The Madeleine climb, on the other hand, was relentless all the way up. — Jessica Hopkins, New York Times, 4 Aug. 2026

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