noun (n)

• a taxonomist who classifies organisms into many groups on the basis of relatively minor characteristics(noun.person)

  Synonym:
  splitter
  Antonym:
  lumper
  

  source: wordnet30
• a person who separates something into parts or groups(noun.person)

  source: wordnet30
• a vertical structure that divides or separates (as a wall divides one room from another)(noun.artifact)

  Synonym:
  partition
  

  source: wordnet30
• a drafting instrument resembling a compass that is used for dividing lines into equal segments or for transferring measurements(noun.artifact)

  source: wordnet30
• One who, or that which, divides; that which separates anything into parts.(noun)

  source: webster1913