facial hair vs beard

facial hair and beard both are nouns.

Word	Noun	Adjective	Verb	Adverb
facial hair	Yes	No	No	No
beard	Yes	No	Yes	No

As nouns, beard is a hyponym of facial hair; that is, beard is a word with a more specific, narrower meaning than facial hair:

Other hyponyms of facial hair include face fungus, whiskers, moustache, mustache, burnside, mutton chop, side-whiskers, sideburn.

facial hair (noun)	beard (noun)
hair on the face (especially on the face of a man)	tuft of strong filaments by which e.g. a mussel makes itself fast to a fixed surface
	hairy growth on or near the face of certain mammals
	the hair growing on the lower part of a man's face
	a person who diverts suspicion from someone (especially a woman who accompanies a male homosexual in order to conceal his homosexuality)
	a tuft or growth of hairs or bristles on certain plants such as iris or grasses

facial hair (verb)	beard (verb)
	go along the rim, like a beard around the chin