inhabitancy vs inhabitation

inhabitancy and inhabitation both are nouns.

Word	Noun	Adjective	Verb	Adverb
inhabitancy	Yes	No	No	No
inhabitation	Yes	No	No	No

As nouns, inhabitancy and inhabitation are synonyms defined as:

inhabitancy and inhabitation: the act of dwelling in or living permanently in a place (said of both animals and men)

Other synonyms of inhabitancy include habitation.

inhabitancy (noun)	inhabitation (noun)
the act of dwelling in or living permanently in a place (said of both animals and men)	the act of dwelling in or living permanently in a place (said of both animals and men)