mu·ta·tion (myo?o-t??sh?n)n.1. The act or process of being altered or changed.2. An alteration or change, as in nature, form, or quality.3. Genetics a. A change in the nucleotide sequence of the genome of an organism or virus, sometimes resulting in the appearance of a new character or trait not found in the parental type.b. The process by which such a change occurs, either through an alteration in the nucleotide sequence coding for a gene or through a change in the physical arrangement of the genetic material.c. The nucleotide sequence, trait, or individual that results from such a change.4. Linguistics a. A change affecting a sound or a class of sounds, such as back vowels or plosive consonants, through assimilation to another sound, as in the process of umlaut.b. A change affecting a sound or a class of sounds that is conditioned by morphological or syntactic factors rather than purely phonological factors, as in Irish, where certain words cause the lenition of the initial consonants of the following word.[Middle English mutacioun, from Old French mutacion, from Latin m?t?ti?, m?t?ti?n-, from past participle of m?t?re, to change; see mutate.]mu·ta?tion·al adj.mu·ta?tion·al·ly adv.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.mutation (mju??te???n) n1. (Genetics) the act or process of mutating; change; alteration2. a change or alteration3. (Genetics) a change in the chromosomes or genes of a cell. When this change occurs in the gametes the structure and development of the resultant offspring may be affected. See also inversion114. (Genetics) another word for mutant15. (Genetics) a physical characteristic of an individual resulting from this type of chromosomal change6. (Phonetics & Phonology) phonetics a. (in Germanic languages) another name for umlautb. (in Celtic languages) a phonetic change in certain initial consonants caused by a preceding word mu?tational adj mu?tationally advCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014mu?ta?tion (myu?te? ??n) n. 1. Biol. a. a sudden departure from the parent type in one or more heritable characteristics, caused by a change in a gene or a chromosome. b. an individual, species, or the like resulting from such a departure. 2. the act or process of changing. 3. a change or alteration, as in form or nature. 4. a change in a speech sound caused by assimilation to a nearby sound, esp. umlaut. [1325?75; Middle English