mutation -
n. 1 the process or an instance of change or alteration.
2 a genetic change which, when transmitted to offspring, gives rise to heritable variations.
3 a mutant.
4 a an umlaut. b (in a Celtic language) a change of a consonant etc.
determined by a preceding word.
mutational adj. mutationally adv. [ME f. L mutatio f. mutare change]