binomial nomenclature n a system of nomenclature in which each species of animal or plant receives a name of two terms of which the first identifies the genus to which it belongs and the second the species itself
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the nomenclature used in scientific classification of living organisms in which each organism is designated by two latinized names (genus and species), both of which must always be used because species names are not necessarily unique. NOTE: The genus name is always capitalized, the species name is not, and both are italicized, e.g., Escherichia coli. When a name is repeated the genus name may be abbreviated by its initial, e.g., E. coli.Medical dictionary. 2011.