The Collaborative International Dictionary of English v.0.48:
Voiceless \Voice"less\, a.
1. Having no voice, utterance, or vote; silent; mute; dumb.
[1913 Webster]
I live and die unheard,
With a most voiceless thought, sheathing it as a
sword. --Byron.
[1913 Webster]
2. (Phon.) Not sounded with voice; as, a voiceless consonant;
surd.
[1913 Webster]
Voiceless stop (Phon.), a consonant made with no audible
sound except in the transition to or from another sound; a
surd mute, as p, t, k.
[1913 Webster] -- Voice"less*ly, adv. --
Voice"less*ness, n.
[1913 Webster]