What does "triathlon" mean?

An athletics event in which contestants compete in swimming, cycling and running in turn.

How do you pronounce "triathlon"?

Pronounced //tɹaɪˈæθˌlɑn//.

Common synonyms include: endurance conditioning, endurance race, multisport event, multisport training, three discipline race, three part challenge.

/tɹaɪˈæθˌlɑn/ noun

noun ·Rare ·Advanced level

Noun

1
An athletics event in which contestants compete in swimming, cycling and running in turn.
2
A former Olympic athletics event in which contestants compete in long jump, shot put, and 100-yard dash. historical
3
Generally, a sports event in which contestant compete in a combination of three sports.

"A triathlon is a forbidding test of endurance."

From tri- + -athlon.