complete or total (used as an intensifier--typically when stressing how bad something is)
Liza, utterly bewildered, stares helplessly at him.
Unfortunately he knew nothing else; and Eliza, though she could count money up to eighteen shillings or so, and had acquired a certain familiarity with the language of Milton from her struggles to qualify herself for winning Higgins’s bet, could not write out a bill without utterly disgracing the establishment.
She drops her work, losing her self-possession utterly at the spectacle of her father’s splendor] A—a—a—a—a—ah—ow—ooh!
There are no more uses of "utter" identified with this meaning, but check unspecified meaning below.
Show samples from other sources
She suffered utter devastation when her child died in the accident.
HIGGINS [loftily] I cannot charge myself with having ever uttered it, Mrs. Pearce.
A woman who utters such depressing and disgusting sounds has no right to be anywhere—no right to live.
She’s a triumph of your art and of her dressmaker’s; but if you suppose for a moment that she doesn’t give herself away in every sentence she utters, you must be perfectly cracked about her.
I don’t believe I could utter one of the old sounds if I tried.
The slippers came bang into my face the moment I entered the room—before I had uttered a word.
She was, in short, an utter failure, an ignorant, incompetent, pretentious, unwelcome, penniless, useless little snob; and though she did not admit these disqualifications (for nobody ever faces unpleasant truths of this kind until the possibility of a way out dawns on them) she felt their effects too keenly to be satisfied with her position.