pious vs religious

pious is not a noun while religious is a noun.

Word	Noun	Adjective	Verb	Adverb
pious	No	Yes	No	No
religious	Yes	Yes	No	No

pious (noun)	religious (noun)
	a member of a religious order who is bound by vows of poverty and chastity and obedience

pious (adjective)	religious (adjective)
having or showing or expressing reverence for a deity	having or showing belief in and reverence for a deity
	of or relating to clergy bound by monastic vows
	concerned with sacred matters or religion or the church
	extremely scrupulous and conscientious