documentary vs existent

documentary is a noun but existent is not a noun.

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

documentary (noun)	existent (noun)
a film or TV program presenting the facts about a person or event

documentary (adjective)	existent (adjective)
relating to or consisting of or derived from documents	having existence or being or actuality
(of film, television, radio, or photography) depicting a real-life event using images or interviews with people involved in the event	being or occurring in fact or actuality; having verified existence; not illusory
	presently existing in fact and not merely potential or possible