(linguistics) An alteration a particular sound of a word, especially the initial consonant, which is triggered by the word's morphological or syntactic context and not by its phonological context.
“The talking head voices her objection from the pan and begins to communicate telepathically with a horrific mutant that the doctor has locked up in a nearby closet.”
“Mutationism was opposed by many naturalists, particularly biometricians like Briton Karl Pearson who defended Darwinian natural selection as the major cause of evolution.”