Source : Webster's Revised Unabridged Dictionary (1913)

Voiceless \Voice"less\, a.
   1. Having no voice, utterance, or vote; silent; mute; dumb.

            I live and die unheard, With a most voiceless
            thought, sheathing it as a sword.     --Byron.

   2. (Phon.) Not sounded with voice; as, a voiceless consonant;
      surd.

   {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. -- {Voice"less*ly}, adv. --
      {Voice"less*ness}, n.