System of naming organisms in which each organism is indicated by two words, the
genus (capitalized) and
species (lowercase) names, both written in italics. For example, the tea rose is
Rosa odorata; the common horse is
Equus caballus. The system was developed by
Carolus Linnaeus in the mid 18th century. The number of binomial names proliferated as new species were established and more categories were formed, and by the late 19th century the nomenclature of many groups of organisms was confused. International committees in the fields of zoology, botany, bacteriology, and virology have since established rules to clarify the situation.
See also taxonomy.
For more information on binomial nomenclature, visit Britannica.com.