fool's cap vs dunce cap

fool's cap and dunce cap both are nouns.

Word	Noun	Adjective	Verb	Adverb
fool's cap	Yes	No	No	No
dunce cap	Yes	No	No	No

As nouns, fool's cap and dunce cap are synonyms defined as:

fool's cap and dunce cap: a cone-shaped paper hat formerly placed on the head of slow or lazy pupils

Other synonyms of fool's cap include dunce's cap.

fool's cap (noun)	dunce cap (noun)
a cone-shaped paper hat formerly placed on the head of slow or lazy pupils	a cone-shaped paper hat formerly placed on the head of slow or lazy pupils