human head vs bean

human head and bean both are nouns.

Word	Noun	Adjective	Verb	Adverb
human head	Yes	No	No	No
bean	Yes	No	Yes	No

As nouns, bean is a hyponym of human head; that is, bean is a word with a more specific, narrower meaning than human head:

Other hyponyms of human head include bullethead, attic, bonce, dome, noggin, noodle.

human head (noun)	bean (noun)
the head of a human being	informal terms for a human head
	any of various edible seeds of plants of the family Leguminosae used for food
	any of various leguminous plants grown for their edible seeds and pods
	any of various seeds or fruits that are beans or resemble beans

human head (verb)	bean (verb)
	hit on the head, especially with a pitched baseball