routine vs rat race

routine and rat race both are nouns.

Word	Noun	Adjective	Verb	Adverb
routine	Yes	Yes	No	No
rat race	Yes	No	No	No

As nouns, rat race is a hyponym of routine; that is, rat race is a word with a more specific, narrower meaning than routine:

Other hyponyms of routine include groove, rut.

routine (noun)	rat race (noun)
an unvarying or habitual method or procedure	an exhausting routine that leaves no time for relaxation
a set sequence of steps, part of larger computer program
a short performance that is part of a longer program

routine (adjective)	rat race (adjective)
found in the ordinary course of events