singer vs sing

singer is a noun but sing is not a noun.

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

singer (noun)	sing (noun)
a person who sings

singer (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