residence vs residency

residence and residency both are nouns.

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

As nouns, residence and residency are synonyms defined as:

Other synonyms of residence include abidance.

residence (noun)	residency (noun)
the act of dwelling in a place	the act of dwelling in a place
the official house or establishment of an important person (as a sovereign or president)	the position of physician who is receiving special training in a hospital (usually after completing an internship)
a large and imposing house
any address at which you dwell more than temporarily