triathlon

noun

tri·​ath·​lon trī-ˈath-lən How to pronounce triathlon (audio)
-ˌlän
nonstandard -ˈa-thə-
Synonyms of triathlonnext
: an athletic contest that is a long-distance race consisting of three phases (such as swimming, bicycling, and running)

Examples of triathlon in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Hers is a spectacular rise — a list of remarkable achievements for someone who only started road cycling in the last few years, having previously competed nationally in duathlon (triathlon without the swimming). — Jessica Hopkins, New York Times, 4 Aug. 2026 The Prince and Princess of Wales have shared tidbits over the years about their three children's — Prince George, Princess Charlotte, 11, and Prince Louis, 8 — interest in sports, with Prince George trying everything from soccer to a triathlon. — Stephanie Petit, PEOPLE, 21 July 2026 Back in the water The operation was timed to be ready for the Olympic triathlon and marathon swimming events. — Camille Knight, CNN Money, 4 July 2026 There are many different ways to take active vacations including niches such as white water rafting, surfing schools, yoga retreats, and triathlon training camps. — Larry Olmsted, Forbes.com, 29 June 2026 See All Example Sentences for triathlon

Word History

Etymology

tri- + -athlon (as in decathlon)

First Known Use

1924, in the meaning defined above

Time Traveler
The first known use of triathlon was in 1924

Browse Nearby Words

triathlete
triathlon
triatic stay
See all Nearby Words

Cite this Entry

“Triathlon.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/triathlon. Accessed 14 Aug. 2026.

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Kids Definition

triathlon

noun
tri·​ath·​lon ˌtrī-ˈath-ˌlän How to pronounce triathlon (audio)
: an athletic contest that is a long-distance race consisting of three phases (as swimming, bicycling, and running)

More from Merriam-Webster on triathlon

Thesaurus: All synonyms and antonyms for triathlon

Britannica.com: Encyclopedia article about triathlon

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