tireless

adjective

tire·​less ˈtī(-ə)r-ləs 

: seemingly incapable of tiring : indefatigable

a tireless worker

tirelessly adverb

tirelessness noun

Synonyms of tireless

• meticulous
• indefatigable
• relentless
• unflagging
• conscientious
• untiring
• active
• vigorous
• diligent
• energetic
• inexhaustible
• intense

Examples of tireless in a Sentence

She has been a tireless advocate for reform.

a tireless advocate for human rights

Recent Examples on the Web

The film seeks to celebrate Guillén’s life while honoring the tireless advocacy of her family, whose campaigning inspired lasting legislative change and amplified the voices of military families. — Andreas Wiseman, Deadline, 19 Aug. 2026

Banks, the first saxophonist to receive the prestigious Avery Fisher Award, is a tireless advocate for his instrument in the classical world. — Beth Wood, San Diego Union-Tribune, 16 Aug. 2026

Colleagues say Garcia is a tireless worker at a hotel and a Hell's Kitchen restaurant who never turned down a shift. — Jesse Zanger, CBS News, 10 Aug. 2026

Yukov was known for his tireless efforts to bring closure to the families of those killed in the war. — Scott Neuman, NPR, 8 Aug. 2026

Word History

First Known Use

1605, in the meaning defined above

Rhymes for tireless

• fireless

Kids Definition

tireless

adjective

tire·​less ˈtī(ə)r-ləs 

: seeming never to get tired

a tireless worker

tirelessly adverb