adulthood vs maturity

adulthood and maturity both are nouns.

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

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

adulthood: the state (and responsibilities) of a person who has attained maturity
maturity: state of being mature; full development

Other hypernyms of adulthood include matureness.

As nouns, adulthood and maturity are synonyms defined as:

adulthood and maturity: the period of time in your life after your physical growth has stopped and you are fully developed

adulthood (noun)	maturity (noun)
the state (and responsibilities) of a person who has attained maturity	state of being mature; full development
the period of time in your life after your physical growth has stopped and you are fully developed	the period of time in your life after your physical growth has stopped and you are fully developed
	the date on which an obligation must be repaid