prothalamion vs song

prothalamion and song both are nouns.

Word	Noun	Adjective	Verb	Adverb
prothalamion	Yes	No	No	No
song	Yes	No	No	No

As nouns, song is a hypernym of prothalamion; that is, song is a word with a broader meaning than prothalamion:

Other hypernyms of prothalamion include epithalamium, vocal.

prothalamion (noun)	song (noun)
a song in celebration of a marriage	the act of singing
	a short musical composition with words
	the characteristic sound produced by a bird
	a distinctive or characteristic sound
	a very small sum