dunce cap vs fool's cap

dunce cap and fool's cap both are nouns.

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

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

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

Other synonyms of dunce cap include dunce's cap.

dunce cap (noun)	fool's 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