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

Humans chose the victim, supplied credentials and set up the attack infrastructure, but instead of human collaborators, AI was used as a trusty, fast, tireless cybercrime assistant. — Ron Schmelzer, Forbes.com, 10 July 2026

Honoring first responders During a ceremony on July 4, acting Venezuelan President Delcy Rodriguez honored rescuers from 18 countries and their search dogs for their tireless efforts in helping the country recover. — Pat Mueller, USA Today, 7 July 2026

Instead, Alfonzo’s first appearance, the culmination of nine tireless years, was somber , stricken by the grief overshadowing what should’ve been a joyous moment in the Dodgers’ to the Padres. — Liana Handler follow, Los Angeles Times, 6 July 2026

Cristobal studies tape of every player UM signs, but Smith does a lot of the necessary legwork, because even Cristobal — with his tireless work ethic — can’t do everything. — Barry Jackson, Miami Herald, 3 July 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