1. the act or process of being altered or changed.
2. an alteration or change, as in nature, form, or quality.
3. genetics A change of the dna sequence within a gene or chromosome of an organism resulting in the creation of a new character or trait not found in the parental type.
4. genetics the process by which such a change occurs in a chromosome, either through an alteration in the nucleotide sequence of the dna coding for a gene or through a change in the physical arrangement of a chromosome.
5. genetics A mutant.
6. linguistics the change that is caused in a sound by its assimilation to another sound, such as umlaut.

1. any alteration or change
2. any heritable change of the base-pair sequence of genetic material
3. a mutant
4. 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
5. this sense?) collective noun for a collection of thrushes

1. change; alteration, either in form or qualities.
2. gradual definitely tending variation, such as may be observed in a group of organisms in the fossils of successive geological levels.
3.
4. as now employed (first by de Vries), a cellular process resulting in a sudden inheritable variation (the offspring differing from its parents in some well-marked character or characters) as distinguished from a gradual variation in which the new characters become fully developed only in the course of many generations. the occurrence of mutations, the selection of strains carrying mutations permitting enhanced survival under prevailing conditions, and the mechanism of hereditary of the characters so appearing, are well-established facts; whether and to what extent the mutation process has played the most important part in the evolution of the existing species and other groups of organisms is an unresolved question.
5. the result of the above process; a suddenly produced variation.
6. a variant strain of an organism in which the hereditary variant property is caused by a mutation{3}.

1. the act or process of changing; change; variableness.
2. rotation; succession.
3. in phonetics, the change of a vowel through the influence of an a, i, or u in the following syllable: proposed for rendering german umlaut into english.
4. in music:
5. in medieval solmization, the change or passage from one hexachord to another, involving a change of the syllable applied to a given tone.
6. in violin-playing, the shifting of the hand from one position to another.
7. the change or alteration in a boy's voice at puberty.
8. in french law, transfer by purchase or descent.
9. A post-house.
10. in biology:
11. A sudden and inheritable change of type; a discontinuous variation; a sport.
12. one of a group of individuals which originate directly and immediately from pure-bred stock and have uniform or nearly uniform characteristics different from those of the parents. mutations differ in form from their parents in much the same manner as closely related species differ from each other. the seeds from a single plant of one of the evening primroses. Œnothcra Lamarckiana, often produce several mutations in the first generation.

1. (genetics) any event that changes genetic structure; any alteration in the inherited nucleic acid sequence of the genotype of an organism
2. (biology) an organism that has characteristics resulting from chromosomal alteration
3. a change or alteration in form or qualities