Soldiers in the army have to shave their heads

Shaving is removing hair from the face or other body part with a razor.

"Shaving" often refers to men who cut their facial hair with a razor or clipper. Sometimes they just trim their facial hair while other men completely shave it. Some people do not shave the chin, this is called a goatee beard. Other men do not shave the upper lip, this is called a mustache.