3. (noun)champion, fighter, hero, paladin someone who fights for a cause
4. (noun)Hero, Heron, Hero of Alexandria Greekmathematician and inventor who devised a way to determine the area of a triangle and who described various mechanical devices (first century)
7. (noun)bomber, grinder, hero, hero sandwich, hoagie, hoagy, Cuban sandwich, Italian sandwich, poor boy, sub, submarine, submarine sandwich, torpedo, wedge, zep a largesandwich made of a long crusty rollsplit 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