noun (n)

• (biology) an organism that has characteristics resulting from chromosomal alteration(noun.person)

  Synonym:
  mutant, sport, variation
  

  source: wordnet30
• (genetics) any event that changes genetic structure; any alteration in the inherited nucleic acid sequence of the genotype of an organism(noun.event)

  Synonym:
  chromosomal mutation, genetic mutation
  

  source: wordnet30
• a change or alteration in form or qualities(noun.event)

  source: wordnet30
• Change; alteration, either in form or qualities.(noun)

  source: webster1913
• Gradual definitely tending variation, such as may be observed in a group of organisms in the fossils of successive geological levels.(noun)

  source: webster1913