A clean-shaven man has no beard and no moustache. He shaves, so the skin of the face shows. It is the usual opposite of bearded. You hear it when looks matter — a job, a uniform, the stage — and in older writing it can sound like praise: tidy, proper. Though actually, it only means the hair is gone. It says nothing about whether the rest of him is tidy. Women are almost never described this way, even when they shave; the word belongs to men’s faces. “Clean” here does not mean “washed.” It means “clear of hair.”