song vs sing

song is a noun but sing is not a noun.

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

song (noun)	sing (noun)
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

song (verb)	sing (verb)
	make a whining, ringing, or whistling sound
	divulge confidential information or secrets
	to make melodious sounds
	produce tones with the voice
	deliver by singing