kook vs odd fellow

kook and odd fellow both are nouns.

Word	Noun	Adjective	Verb	Adverb
kook	Yes	No	No	No
odd fellow	Yes	No	No	No

As nouns, kook and odd fellow are synonyms defined as:

kook and odd fellow: someone regarded as eccentric or crazy and standing out from a group

Other synonyms of kook include odd fish, odd man out, queer bird, queer duck.

kook (noun)	odd fellow (noun)
someone regarded as eccentric or crazy and standing out from a group	someone regarded as eccentric or crazy and standing out from a group