siss vs utter

siss is not an adjective while utter is an adjective.

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

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

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

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

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

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

siss (verb)	utter (verb)
make a sharp hissing sound, as if to show disapproval	express in speech
express or utter with a hiss	articulate; either verbally or with a cry, shout, or noise
	express audibly; utter sounds (not necessarily words)
	put into circulation