/myo͞oˈtāSHən/
Noun, pl. mutations
1. A change of the nucleotide sequence of the genome of an organism, virus, or extra-chromosomal genetic element. Mutations result from unrepaired damage to DNA or to RNA genomes (typically caused by radiation or chemical mutagens), from errors in the process of replication, or from the insertion or deletion of segments of DNA by mobile genetic elements. Mutations may or may not produce discernible changes in the observable characteristics (phenotype) of an organism. Mutations play a part in both normal and abnormal biological processes, including evolution, cancer, and the development of the immune system. (wikipedia.org)
2. A permanent, heritable change in the nucleotide sequence in a gene or a chromosome; the process in which such a change occurs in a gene or in a chromosome. (biology-online.org)
3. The changing of the structure of a gene, resulting in a variant form that may be transmitted to subsequent generations, caused by the alteration of single base units in DNA, or the deletion, insertion, or rearrangement of larger sections of genes or chromosomes. (Google Dictionary)
4. Any alteration or change. (wiktionary.org)
5. Any heritable change of the base-pair sequence of genetic material. (wiktionary.org)
6. A mutant. (wiktionary.org)
7.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. (wiktionary.org)
Word origin: From Latin mutationem (nominative mutatio) “a changing, alteration, a turn for the worse,” noun of action from past participle stem of mutare “to change.”