EPHEBI, in Grecian Antiquity, the name given to the Attic youth from the age of eighteen till they entered upon their twentieth year. During this period they served a sort of apprenticeship in arms, and were frequently sent, under the name of peripoli, to some of the frontier towns of Attica to keep watch against foreign invasion. It is not precisely determined whether the ephibi enjoyed all the rights of citizens; but the most received opinion is, that they were entitled to some of them at least. The well-known instance of Demosthenes, who at the age of eighteen prosecuted his guardians for mismanaging his property, is a confirmation of this idea.