Wincing Devil, I think your dictionary's definition 1d (one who shows great courage) comes closest to your own. I have the same dictionary here, and one of the definitions under "heroic" is "grand; noble". It also mentions honor, which I think is a key component of a hero's makeup.

Pedant alert! The plural of the English word "hero" is actually "heroes", though it is often misspelled as "heros".

Here's a page about Hero and Leander (PARENTS TAKE NOTE: At the top of this page is a statue of Hero, unclothed, so depending on your opinion of the nude figure in art, you may or may not want to shield your kids' eyes): http://homepage.mac.com/cparada/GML/Hero.html

Now, the sandwich of which Don speaks is not universally known as a "hero". Depending on which part of the US you're in when you make one, it's a grinder, a submarine, a hoagie, a muffuletta, or a po' boy. But whatever you call it, don't forget the tomatoes... and put some hot peppers on mine, will ya?