genus | ˈdʒiːnəs, ˈdʒɛnəs | noun (plural genera | ˈdʒɛnərə | ) Biology a principal taxonomic category that ranks above species and below family, and is denoted by a capitalized Latin name, e.g. Leo. • (in philosophical and general use) a class of things that have common characteristics and that can be divided into subordinate kinds.