triathlon

noun

tri·​ath·​lon trī-ˈath-lən 

-ˌlän

nonstandard -ˈa-thə-

: 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

Lincoln Sabini was a member of the UC Davis triathlon sports club, was involved with the Davis Bike Collective and cycled regularly. — Madison Smalstig, Sacbee.com, 17 Sep. 2026

Athletes will be at the heart of this next chapter alongside Marjolaine Pierré, Julie Iemmolo and Casper Stornes, three athletes who already compete at the highest level of long-distance triathlons. — Stephen Garner, Footwear News, 10 Sep. 2026

An endurance athlete, Steinberg spent a decade completing various marathons and Ironman triathlons to help manage his mental health following a depression spell during college. — Vikram Murthi, IndieWire, 5 Sep. 2026

Thousands of athletes from around the world descended on Chicago this weekend, ready to test months of training at the country’s largest triathlon. — Lila Hempel-Edgers, Chicago Tribune, 22 Aug. 2026

Word History

Etymology

tri- + -athlon (as in decathlon)

First Known Use

1924, in the meaning defined above

Kids Definition

triathlon

noun

tri·​ath·​lon ˌtrī-ˈath-ˌlän 

: an athletic contest that is a long-distance race consisting of three phases (as swimming, bicycling, and running)