endemic vs autochthonic

endemic is a noun but autochthonic is not a noun.

Word	Noun	Adjective	Verb	Adverb
endemic	Yes	Yes	No	No
autochthonic	No	Yes	No	No

As adjectives, endemic and autochthonic are synonyms defined as:

Other synonyms of endemic include autochthonal, autochthonous, indigenous.

endemic (noun)	autochthonic (noun)
a plant or animal that is native to a certain limited area
a disease that is constantly present to a greater or lesser degree in people of a certain class or in people living in a particular location

endemic (adjective)	autochthonic (adjective)
of or relating to a disease (or anything resembling a disease) constantly present to greater or lesser extent in a particular locality	originating where it is found
native to or confined to a certain region
originating where it is found