tireless

[tahyuhr-lis]

adjective

1. never seeming to tire; not slackening: his tireless efforts.

   a tireless worker;

   his tireless efforts.

   Synonyms: unfaltering, hardworking, industrious, unwearied

tireless

/ ˈtaɪəlɪs /

adjective

1. unable to be tired; indefatigable

Other Word Forms

• tirelessly adverb
• tirelessness noun

Word History and Origins

Origin of tireless¹

First recorded in 1585–95; tire ¹ + -less

Example Sentences

He wasn’t around to see his onetime tireless assistant coach restore the 49ers to glory — including falling five yards shy of a Super Bowl victory.

From Los Angeles Times

De Minaur, a tireless defensive player, wrestled the break back but Auger-Aliassime regained his advantage in the next game before closing out the set.

From BBC

"He's been a tireless campaigner since his release, and I don't think that this is necessarily the end of the matter," he added.

From BBC

He was a tireless proselytizer for his star client.

From Los Angeles Times

That India roared back says much about their spirit, the tireless effort of their seamers, and the energy they found from their wonderful supporters.

From BBC

Related Words

• energetic 
• enthusiastic 
• indefatigable 
• resolute 
• steadfast 
• strenuous 
• unflagging 
• vigorous