WordNet sense 1 (Greek mathematician and inventor who devised a way to determine the area of a triangle and who described various mechanical devices (first century)):

heron, Hero of Alexandria

WordNet sense 2 (someone who fights for a cause):

champion, fighter, paladin

WordNet sense 3 (a large sandwich made of a long crusty roll split lengthwise and filled with meats and cheese (and tomato and onion and lettuce and condiments); different names are used in different sections of the United States):

bomber, grinder, hoagie, hoagy, sub, submarine, torpedo, wedge, zep, Cuban sandwich, hero sandwich, Italian sandwich, submarine sandwich