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

During his trial, Browne’s defense lawyer, Bruce Udolf, claimed in court that Browne was dogged for 15 years by a relentless federal labor cop and a long line of political enemies, according to Sun Sentinel news archives. —Scott Travis, Sun Sentinel, 13 Mar. 2026

Dhaka, Bangladesh — Every day, Shakil Khan weaves his bike through the relentless traffic of Dhaka, delivering items and ferrying passengers across the city. —Rhea Mogul, CNN Money, 13 Mar. 2026

Ogilvie was already complaining about the job being relentless. —Maggie Fremont, Vulture, 13 Mar. 2026

Signage for new and defunct art galleries appear with letters roasted dry by the relentless California sun until the edges of words peel away, looking like they were written in calligraphy. —Xuan Juliana Wang, Los Angeles Times, 12 Mar. 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