folk song vs folksong

folk song and folksong both are nouns.

Word	Noun	Adjective	Verb	Adverb
folk song	Yes	No	No	No
folksong	Yes	No	No	No

As nouns, folk song and folksong are synonyms defined as:

folk song and folksong: a song that is traditionally sung by the common people of a region and forms part of their culture

Other synonyms of folk song include folk ballad.

folk song (noun)	folksong (noun)
a song that is traditionally sung by the common people of a region and forms part of their culture	a song that is traditionally sung by the common people of a region and forms part of their culture