lifer vs yardbird

lifer and yardbird both are nouns.

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

As nouns, yardbird is a hypernym of lifer; that is, yardbird is a word with a broader meaning than lifer:

Other hypernyms of lifer include con, convict, inmate, yard bird.

lifer (noun)	yardbird (noun)
a prisoner serving a term of life imprisonment	a military recruit who is assigned menial tasks
	a person serving a sentence in a jail or prison