Princeton's WordNet

1. unvoiced, voiceless, surd, hard(adj)

   produced without vibration of the vocal cords

   "unvoiced consonants such as `p' and `k' and `s'"

2. disenfranchised, disfranchised, voiceless, voteless(adj)

   deprived of the rights of citizenship especially the right to vote

   "labor was voiceless"; "disenfrenchised masses took to the streets"

3. breathed, voiceless(adj)

   uttered without voice

   "could hardly hear her breathed plea, `Help me'"; "voiceless whispers"

4. aphonic, voiceless(adj)

   being without sound through injury or illness and thus incapable of all but whispered speech

Wiktionary

1. voiceless(Adjective)

   Lacking a voice, without vocal sound.

2. voiceless(Adjective)

   Spoken without vibration of the vocal cords; unvoiced. Examples: [t], [s], [f].

Webster Dictionary

1. Voiceless(adj)

   having no voice, utterance, or vote; silent; mute; dumb

2. Voiceless(adj)

   not sounded with voice; as, a voiceless consonant; surd

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