hurdy-gurdy vs hurdy gurdy

hurdy-gurdy and hurdy gurdy both are nouns.

Word	Noun	Adjective	Verb	Adverb
hurdy-gurdy	Yes	No	No	No
hurdy gurdy	Yes	No	No	No

As nouns, hurdy-gurdy and hurdy gurdy are synonyms defined as:

hurdy-gurdy and hurdy gurdy: a stringed instrument that produces sounds by means of a wheel that rubs against the strings

Other synonyms of hurdy-gurdy include wheel fiddle.

hurdy-gurdy (noun)	hurdy gurdy (noun)
a stringed instrument that produces sounds by means of a wheel that rubs against the strings	a stringed instrument that produces sounds by means of a wheel that rubs against the strings