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

Swiss brand On is rapidly disrupting Nike's long-standing dominance in the global running footwear market, alongside Hoka, by prioritizing relentless innovation over celebrity endorsements. — Mark Faithfull, Forbes.com, 1 July 2026

The story of America is a story of industry, technical skill, and relentless optimism for what the future holds. — Mark Rayfield, Fortune, 1 July 2026

Back from a hamstring injury, Teoscar Hernández rejoins a relentless Dodgers offense that pounds 17 hits and three homers in a 9-4 win over the Athletics. — Bill Shaikin, Los Angeles Times, 30 June 2026

That is, until you are subjected to the relentless whine of mosquitoes. — Brandee Gruener, Southern Living, 30 June 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