lodging vs residency

lodging and residency both are nouns.

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

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

Other hypernyms of lodging include abidance, residence.

lodging (noun)	residency (noun)
the act of lodging	the act of dwelling in a place
structures collectively in which people are housed	the position of physician who is receiving special training in a hospital (usually after completing an internship)
the state or quality of being lodged or fixed even temporarily