sing vs utter

sing is not an adjective while utter is an adjective.

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

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

Other hypernyms of sing include emit, let loose, let out.

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

Other hypernyms of sing include mouth, speak, talk, verbalise, verbalize.

sing (adjective)	utter (adjective)
	complete and absolute
	without qualification; used informally as (often pejorative) intensifiers

sing (verb)	utter (verb)
make a whining, ringing, or whistling sound	express in speech
divulge confidential information or secrets	articulate; either verbally or with a cry, shout, or noise
to make melodious sounds	express audibly; utter sounds (not necessarily words)
produce tones with the voice	put into circulation
deliver by singing