inmate vs lifer

inmate and lifer both are nouns.

Word	Noun	Adjective	Verb	Adverb
inmate	Yes	No	No	No
lifer	Yes	No	No	No

As nouns, lifer is a hyponym of inmate; that is, lifer is a word with a more specific, narrower meaning than inmate:

Other hyponyms of inmate include trusty.

inmate (noun)	lifer (noun)
one of several resident of a dwelling (especially someone confined to a prison or hospital)	a prisoner serving a term of life imprisonment
a patient who is residing in the hospital where he is being treated
a person serving a sentence in a jail or prison