1. a person of great strength, endurance, or resilience; someone who rarely misses work or competition despite hardship
Usage: informal; often capitalized when referring to the Ironman triathlon brand
2. a competitor in or finisher of an Ironman triathlon, an endurance race consisting of a 2.4-mile swim, 112-mile bike ride, and 26.2-mile run
Usage: often capitalized; trademark sense

Examples

• He's an ironman—he hasn't missed a single game in fifteen years.
• She trained for months to become an Ironman competitor.
• The ironman of the team never complains, no matter how difficult the conditions.
• Completing an Ironman triathlon requires months of dedicated training.
• His ironman work ethic earned him respect from his colleagues.