favor vs good turn

favor and good turn both are nouns.

Word	Noun	Adjective	Verb	Adverb
favor	Yes	No	Yes	No
good turn	Yes	No	No	No

As nouns, good turn is a hyponym of favor; that is, good turn is a word with a more specific, narrower meaning than favor:

Other hyponyms of favor include turn.

favor (noun)	good turn (noun)
an act of gracious kindness	a favor for someone
souvenir consisting of a small gift given to a guest at a party
an advantage to the benefit of someone or something
an inclination to approve
a feeling of favorable regard