1. Noun.  A group of plants or animals having similar appearance.
  2. Noun.  (context, biology) A rank in the classification of organisms, below genus and above subspecies; a taxon at that rank.
  3. Noun.  (mineralogy) A mineral with a unique chemical formula whose crystals belong to a unique crystallographic system.
  4. Noun.  (obsolete) The image of something cast on a surface, or reflected from a surface, or refracted through a lens or telescope; a reflection.
  5. Noun.  (Roman Catholicism) Either of the two elements of the Eucharist after they have been consecrated, so named because they retain the image of the bread and wine before their transubstantiation into the body and blood of Christ.

