mut·ism (myo?o?t?z??m)n. The condition of being unable or unwilling to speak as a result of a physical or psychological disorder.American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.mutism (?mju?t?z?m) n1. the state of being mute2. (Psychiatry) psychiatry a. a refusal to speak although the mechanism of speech is not damagedb. the lack of development of speech, due usually to early deafnessCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014mut?ism (?myu t?z ?m) n. an inability to speak, due to a physical defect, conscious refusal, or psychogenic inhibition. [1815?25] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.mutismPsychiatry. a conscious or unconscious refusal to make verbal responses to questions, present in some mental disorders.See also: Speech-Ologies & -Isms. Copyright 2008 The Gale Group, Inc. All rights reserved.