Definition of "ironman"

ironman

noun
plural ironmen or ironmans
1. An extremely tough and strong athlete, especially one who competes in extreme athletic competitions or in a large number of games consecutively.
2. (Australia) A form of surf lifesaving competition which combines swimming, board paddling, ski paddling and running.
  Quotations
  The catalyst for this rift was the ironman, a multi-discipline sport combining swimming, running, surf-skis and paddle-boards.Introduced to Australia in 1965 by touring American lifeguards, the ironman is a test of stamina, strength, and diverse skill.
  2011, Katrina Marie Russell, Youth Sport in Australia, page 153
3. An extreme form of triathlon, expecially one organised by the World Triathlon Corporation that comprises a 2.4-mile swim, a 112-mile bike race and a marathon run.
  Quotations
  “Every sense of your body is taken over by the climate,” said the New York City native Christopher Bergland, who set a record at triple ironmans (7.2-mile swim, 336-mile bike, 78.6-mile run) but failed to finish one of his three Badwater races.
  2007 July 21, Aimee Berg, “Far-From-Basic Training for a 135-Mile Footrace”, in New York Times‎
4. (by extension) The winner of such a lifesaving event or triathlon.