Definition from Wiktionary, the free dictionary
trinomen (plural trinomina)
- (taxonomy, zoology) A scientific name at the rank of subspecies: an expansion of a binomial name (a genus and a species) combined with the name of the subspecies; for example Anopheles gigas formosus or Homo sapiens sapiens.
- The subspecies (trinomen) is the only infraspecific taxon so recognized by the International Code of Zoological Nomenclature... However, the category of subspecies has not been widely used in entomology, because, in most cases, the level of population differentiation within a species is not clearly determined and subspecies populations are difficult to identify.