essential vs constituent

essential and constituent both are nouns.

Word	Noun	Adjective	Verb	Adverb
essential	Yes	Yes	No	No
constituent	Yes	Yes	No	No

essential (noun)	constituent (noun)
anything indispensable	an artifact that is one of the individual parts of which a composite entity is made up; especially a part that can be separated from or attached to a system
	an abstract part of something
	(grammar) a word or phrase or clause forming part of a larger grammatical construction
	a member of a constituency; a citizen who is represented in a government by officials for whom he or she votes
	something determined in relation to something that includes it

essential (adjective)	constituent (adjective)
basic and fundamental	constitutional in the structure of something (especially your physical makeup)
defining rights and duties as opposed to giving the rules by which rights and duties are established
being or relating to or containing the essence of a plant etc
of the greatest importance
absolutely necessary; vitally necessary