speak vs utter

speak is not an adjective while utter is an adjective.

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

As verbs, speak and utter are synonyms defined as:

Other synonyms of speak include mouth, talk, verbalise, verbalize.

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

speak (verb)	utter (verb)
express in speech	express in speech
exchange thoughts; talk with	articulate; either verbally or with a cry, shout, or noise
use language	express audibly; utter sounds (not necessarily words)
give a speech to	put into circulation
make a characteristic or natural sound