song vs cradlesong

song and cradlesong both are nouns.

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

As nouns, cradlesong is a hyponym of song; that is, cradlesong is a word with a more specific, narrower meaning than song:

Other hyponyms of song include carol, lullaby.

As nouns, cradlesong is a hyponym of song; that is, cradlesong is a word with a more specific, narrower meaning than song:

song (noun)	cradlesong (noun)
the act of singing	the act of singing a quiet song to lull a child to sleep
a short musical composition with words	a quiet song intended to lull a child to sleep
the characteristic sound produced by a bird
a distinctive or characteristic sound
a very small sum