high-hat cymbal vs high hat

high-hat cymbal and high hat both are nouns.

Word	Noun	Adjective	Verb	Adverb
high-hat cymbal	Yes	No	No	No
high hat	Yes	No	No	No

As nouns, high-hat cymbal and high hat are synonyms defined as:

high-hat cymbal (noun)	high hat (noun)
cymbals that are operated by a foot pedal	cymbals that are operated by a foot pedal
	a man's hat with a tall crown; usually covered with silk or with beaver fur