fool vs cuckoo

fool and cuckoo both are nouns.

Word	Noun	Adjective	Verb	Adverb
fool	Yes	No	Yes	No
cuckoo	Yes	No	Yes	No

As nouns, cuckoo is a hyponym of fool; that is, cuckoo is a word with a more specific, narrower meaning than fool:

fool (noun)	cuckoo (noun)
a person who lacks good judgment	any of numerous European and North American birds having pointed wings and a long tail
a person who is gullible and easy to take advantage of	a man who is a stupid incompetent fool
a professional clown employed to entertain a king or nobleman in the Middle Ages

fool (verb)	cuckoo (verb)
indulge in horseplay	repeat monotonously, like a cuckoo repeats his call
fool or hoax
spend frivolously and unwisely
make a fool or dupe of