devoice

[dee-vois]Phonetics
verb (used with object), de·voiced, de·voic·ing.
  1. to pronounce (an ordinarily voiced speech sound) without vibration of the vocal cords; make voiceless.
verb (used without object), de·voiced, de·voic·ing.
  1. to devoice a speech sound.
Also unvoice.

Origin of devoice

First recorded in 1930–35; de- + voice
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for devoice

devoice

devocalize or devocalise (diːˈvəʊkəˌlaɪz)

verb
  1. (tr) phonetics to make (a voiced speech sound) voiceless
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012