recursive routine vs subroutine

recursive routine and subroutine both are nouns.

Word	Noun	Adjective	Verb	Adverb
recursive routine	Yes	No	No	No
subroutine	Yes	No	No	No

As nouns, subroutine is a hypernym of recursive routine; that is, subroutine is a word with a broader meaning than recursive routine:

Other hypernyms of recursive routine include function, procedure, routine, subprogram.

recursive routine (noun)	subroutine (noun)
a routine that can call itself	a set sequence of steps, part of larger computer program