Pronunciation: (myOO-tā'shun),[key] —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.
5. Ling.(in Celtic languages) syntactically determined morphophonemic phenomena that affect initial sounds of words.