The Collaborative International Dictionary
Utterless
Utterless \Ut"ter*less\, a. Incapable of being uttered. [Obs.]
A clamoring debate of utterless things.
--Milton.
Wiktionary
utterless
a. (context obsolete English) Incapable of being uttered.
Usage examples of "utterless".
The expression on his face was seemingly of a kind of utterless emotion that he was feeling when he died.