good word vs kudos

good word and kudos both are nouns.

Word	Noun	Adjective	Verb	Adverb
good word	Yes	No	No	No
kudos	Yes	No	No	No

As nouns, kudos is a hypernym of good word; that is, kudos is a word with a broader meaning than good word:

good word: something that recommends (or expresses commendation of) a person or thing as worthy or desirable
kudos: an expression of approval and commendation

Other hypernyms of good word include congratulations, extolment, praise.

good word (noun)	kudos (noun)
good news	an expression of approval and commendation
something that recommends (or expresses commendation of) a person or thing as worthy or desirable