tireless
Americanadjective
adjective
Other Word Forms
Etymology
Origin of tireless
Explanation
Someone who's tireless seems to never run out of energy. A tireless student will stay up late to make sure her paper is perfect; a tired student will just go to sleep. Your tireless efforts might be just what your friend's campaign for student council president needs—you're energetic and enthusiastic, and you'll focus on the campaign unflaggingly. Another way to say tireless is indefatigable. Tireless etymologists have determined that both adjectives date from the 16th century.
Vocabulary lists containing tireless
"A Noiseless Patient Spider" by Walt Whitman
Looking to grow your vocabulary? Check out this interactive, curated word list from our team of English language specialists at Vocabulary.com – one of over 17,000 lists we've built to help learners worldwide!
Because of Mr. Terupt
Interested in learning more words like this one? Our team at Vocabulary.com has got you covered! You can review flashcards, quiz yourself, practice spelling, and more – and it's all completely free to use!
Pre-AP Theatre
Want to remember this word for good? Start your learning journey today with our library of interactive, themed word lists built by the experts at Vocabulary.com – we'll help you make the most of your study time!
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Stubborn, single-minded and tireless, lionized and controversial, the Los Angeles water boss was 72.
From Los Angeles Times ● Aug. 6, 2026
In their study, published by the Journal of Vertebrate Paleontology in July 2020, the researchers said the name recognized "his tireless work on the Late Cretaceous paleontology of the Southeast and Eastern Seaboard, USA."
From Science Daily ● Aug. 5, 2026
His tireless travel schedule and quick wit testify to his stamina -- and he also credits his third wife Rosangela da Silva, 59, with keeping him young.
From Barron's ● Aug. 2, 2026
Annie Lennox was appointed an OBE for her "tireless charity campaigns and championing of humanitarian causes"
From BBC ● Jul. 15, 2026
Kendra doubted that a team of horses could have matched the tireless speed of his loping strides.
From "Fablehaven" by Brandon Mull
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
