manhood vs adulthood

manhood and adulthood both are nouns.

Word	Noun	Adjective	Verb	Adverb
manhood	Yes	No	No	No
adulthood	Yes	No	No	No

As nouns, adulthood is a hypernym of manhood; that is, adulthood is a word with a broader meaning than manhood:

manhood: the state of being a man; manly qualities
adulthood: the state (and responsibilities) of a person who has attained maturity

manhood (noun)	adulthood (noun)
the status of being a man	the state (and responsibilities) of a person who has attained maturity
the quality of being human	the period of time in your life after your physical growth has stopped and you are fully developed
the state of being a man; manly qualities