library routine vs routine

library routine and routine both are nouns.

Word	Noun	Adjective	Verb	Adverb
library routine	Yes	No	No	No
routine	Yes	Yes	No	No

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

Other hypernyms of library routine include function, procedure, subprogram, subroutine.

library routine (noun)	routine (noun)
a debugged routine that is maintained in a program library	an unvarying or habitual method or procedure
	a set sequence of steps, part of larger computer program
	a short performance that is part of a longer program

library routine (adjective)	routine (adjective)
	found in the ordinary course of events