tenancy vs residency

tenancy and residency both are nouns.

Word	Noun	Adjective	Verb	Adverb
tenancy	Yes	No	No	No
residency	Yes	No	No	No

As nouns, residency is a hypernym of tenancy; that is, residency is a word with a broader meaning than tenancy:

Other hypernyms of tenancy include abidance, residence.

tenancy (noun)	residency (noun)
an act of being a tenant or occupant	the act of dwelling in a place
	the position of physician who is receiving special training in a hospital (usually after completing an internship)