What's the "een" in Halloween?
late 14c., "man of superhuman strength or physical courage," from Latin heros "hero," from Greek heros "demi-god" (a variant singular of which was heroe), originally "defender, protector," from PIE root *ser- "to watch over, protect" (cf. Latin servare "to save, deliver, preserve, protect;" see observe). Meaning "man who exhibits great bravery" in any course of action is from 1660s. Sense of "chief male character in a play, story, etc." first recorded 1690s. First record of hero-worship is from 1774.
1955, the New York term for a sandwich elsewhere called submarine, grinder, poor boy (New Orleans), or hoagie (Philadelphia); origin unknown, perhaps so called for its great size, or a folk etymology alteration of Greek gyro as a type of sandwich.