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

In late 2017, with the help of a tireless pro bono lawyer who worked his case for years, Fred was fully and unconditionally pardoned by the state of Nevada. — Megan Rose, ProPublica, 9 Sep. 2026

Just as significant has been his tireless commitment to giving back and supporting the next generation of screen talent through his charitable work and dedication to the industry, including his work with BAFTA. — Georg Szalai, HollywoodReporter, 9 Sep. 2026

During three seasons as the Rams’ offensive coordinator, Mike LaFleur said McVay established strong foundations but also used his tireless energy to encourage assistants to tear down tried-and-true concepts and build them back, sparking innovation. — Los Angeles Times, 8 Sep. 2026

But perhaps the most impressive thing the seemingly tireless Parton did during her 80 years was donate much of her wealth to impoverished communities. — Donna Vickroy, Chicago Tribune, 28 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