iron man; strong man; person of iron will
Describes a person with exceptional physical or mental toughness, often used metaphorically. Can refer to athletes, workers, or anyone with unyielding determination.
He's an iron man who works ten hours every day.
That athlete is known as an iron man who plays even when injured.
robot; steel-clad robot
Used in fiction, especially for humanoid robots or armored mechanical beings. Common in manga, anime, and tokusatsu.
In that anime, a flying robot appears.
Tetsujin 28-go is a classic Japanese robot manga.
triathlon; ironman race
Compound of 鉄 (iron) and 人 (person). The literal meaning 'iron person' extends metaphorically to a tough individual and, in fiction, to a steel robot.