constituent vs essential

constituent and essential both are nouns.

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

constituent (noun)	essential (noun)
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	anything indispensable
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

constituent (adjective)	essential (adjective)
constitutional in the structure of something (especially your physical makeup)	basic and fundamental
	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