existent vs being

existent is not a noun while being is a noun.

Word	Noun	Adjective	Verb	Adverb
existent	No	Yes	No	No
being	Yes	No	No	No

existent (noun)	being (noun)
	a living thing that has (or can develop) the ability to act or function independently
	the state or fact of existing

existent (adjective)	being (adjective)
having existence or being or actuality
being or occurring in fact or actuality; having verified existence; not illusory
presently existing in fact and not merely potential or possible