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 Cubs have been relentless against lefties this season, and that pressure continued Wednesday with lefty Jackson Kent, a Lake Park graduate from Hanover Park, making his major-league debut for the Nationals. — Meghan Montemurro, Chicago Tribune, 13 Aug. 2026

The brutal nausea and vomiting of norovirus, for instance, subsides in one to three days; even the relentless diarrhea of cyclosporiasis can let up in a couple of days with an antibiotic. — Erica Sloan, Washington Post, 12 Aug. 2026

It’s been my privilege to learn, from scholars and thinkers and writers far more deeply rooted than myself in the American west, about its realities and relentless contradictions. — Literary Hub, 11 Aug. 2026

The matter has escalated to litigation Once a creditor decides to sue over a debt, communication frequently shifts from the call center to a legal team, and the phone calls that once felt relentless can stop abruptly. — Angelica Leicht, CBS News, 11 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