Kinship group or clan. Plural is gene.

origin, descent] An early period of rapid embryonic development in which the organs take form from the primary germ layers.

Genos (plural gene, "clan") is the ancient Greek term for small kinship groups which identified themselves as a unit, referred to by a single name. Most gene seem to have been composed of noble families—Herodutus uses the term to denote noble families—and much of early Greek politics seems to have involved struggles between gene. Gene are best attested at Athens, where writers from Herodotus to Aristotle dealt with them.