quaver vs sing

quaver is a noun but sing is not a noun.

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

As verbs, sing is a hypernym of quaver; that is, sing is a word with a broader meaning than quaver:

quaver: sing or play with trills, alternating with the half note above or below
sing: produce tones with the voice

quaver (noun)	sing (noun)
a musical note having the time value of an eighth of a whole note
a tremulous sound

quaver (verb)	sing (verb)
sing or play with trills, alternating with the half note above or below	make a whining, ringing, or whistling sound
give off unsteady sounds, alternating in amplitude or frequency	divulge confidential information or secrets
	to make melodious sounds
	produce tones with the voice
	deliver by singing