Definition of "unvoiced" []

• Not expressed or uttered: unvoiced fears. (adjective)
• Linguistics Voiceless: unvoiced consonants. (adjective)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "In tracing the characteristic phenomenon of life from simple beginnings in that vast region which may be called unvoiced, as exemplified in the world of plants, to its highest expression in the animal kingdom, one is repeatedly struck by the one dominant fact that in order to maintain an organism at the height of its efficiency something more than a mechanical perfection of its structure is necessary."
• "Over at Bell Labs, "shh" is called unvoiced fricatives, or "unvoiced hiss energy," pulmonary turbulence modulated by tongue, teeth and lips."
• ""In tracing the characteristic phenomena of life from simple beginnings in that vast region which may be called unvoiced, as exemplified in the world of plants, to its highest expression in the animal kingdom, one is repeatedly struck by the one dominant fact that in order to maintain an organism at the height of its efficiency something more than a mechanical perfection of its structure is necessary."