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

The relentless heat wave which has set hundreds of June records — and even all-time records — across western Europe in the past days is set to expand, bringing dangerous heat to much of the United Kingdom. — Taylor Ward, CNN Money, 24 June 2026

The play came after a relentless attack by England that started with a shot from Bukayo Saka at Ghana's goal. — Monica Alba, NBC news, 24 June 2026

For others, particularly those drowning in medical bills or facing relentless collection efforts, the clean break a discharge provides is worth far more than the protection that's failing to bring them peace. — Angelica Leicht, CBS News, 23 June 2026

The Hawks traded Young in January, but opponents continued their relentless attack at the rim. — Michael Cunningham, AJC.com, 23 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