irreligious vs religious

irreligious is not a noun while religious is a noun.

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

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

irreligious (adjective)	religious (adjective)
hostile or indifferent to religion	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