In biological classification, the order (Latin: ordo) is 1. * a taxonomic rank used in the classification of organisms and recognized by the nomenclature codes. The well-known ranks in descending order are: life, domain, kingdom, phylum, class, order, family, genus, and species, with order fitting in between class and family. An immediately higher rank, superorder, is sometimes added directly above order, with suborder directly beneath order. 2. * a taxonomic unit (a taxon; plural taxa) in the rank of order (e.g. Strigiformes, Rosales). In that case the plural is orders (Latin ordines).