genu

n.; pl. Genera [ L., birth, race, kind, sort; akin to Gr. &unr_;. See Gender, and cf. Benign. ] [ 1913 Webster ]

1. (Logic) A class of objects divided into several subordinate species; a class more extensive than a species; a precisely defined and exactly divided class; one of the five predicable conceptions, or sorts of terms. [ 1913 Webster ]

2. (Biol.) An assemblage of species, having so many fundamental points of structure in common, that in the judgment of competent scientists, they may receive a common substantive name. A genus is not necessarily the lowest definable group of species, for it may often be divided into several subgenera. In proportion as its definition is exact, it is natural genus; if its definition can not be made clear, it is more or less an artificial genus. [ 1913 Webster ]

☞ Thus in the animal kingdom the lion, leopard, tiger, cat, and panther are species of the Cat kind or genus, while in the vegetable kingdom all the species of oak form a single genus. Some genera are represented by a multitude of species, as Solanum (Nightshade) and Carex (Sedge), others by few, and some by only one known species. [ 1913 Webster ]

Subaltern genus (Logic), a genus which may be a species of a higher genus, as the genus denoted by quadruped, which is also a species of mammal. --
Summum genus [ L. ] (Logic), the highest genus; a genus which can not be classed as a species, as being. [ 1913 Webster ]