noun.

A word that has recently been overused in the American English vocabulary. It has been automatically bestowed upon people in the law enforcement, armed forces, or fire/rescue services, as well as presidents. I.e. police officers, soldiers, and fire fighters and paramedics. A hero, however, does not require wearing a uniform or be involved in such professions listed above.

The basic definition of a hero is one who does not recognize such declarations bestowed upon them by others and accomplishes an act or acts which are deemed extraordinary and exceeds the call of duty. This act or acts usually involves the intention or consequence of saving another person(s) life or rescuing another from impending harm.

Defined in the movie Serenity:

A hero is someone who gets a lot of OTHER people killed.

Someone who helps without anything expected in return. Their gesture may be big or small, profound or not, it doesn't make im' any less of a hero.

one who lays down his own life so that others can live

A man or women willing to sacrifice themself to help others without the consideration of there own safety.
"Those who face fire without fear or armor.Those who step into the darkness without assurances of ever walking out again, because they know there are others waiting in the dark, Awaiting salvation."

A Submarine Sandwich. The long sandwich featuring layers of meat and cheese on a crusty Italian roll goes by a variety of names. Submarine, sub, and hero are widespread. Localized terms are bomber (upstate New York), wedge (downstate New York), hoagie (Delaware Valley, including Philadelphia and southern New Jersey), grinder (New England), Cuban sandwich (Miami), Italian sandwich (Maine), Italian (southern Midwest), and poor boy (New Orleans, before Katrina) now goes by soggy boy.

A valiant person; A submarine sandwich; A Chinese-American greeting word.

A person who voluntarily gives of themselves without expecting anything in return. In doing so they exhibit some sort of exceptional character trait. They also possess traits that make them a role model for others.