Of or relating to Protagoras or his philosophy; (of a philosophy, system of thought, etc.) specifically characterized by relativism, agnosticism, or scepticism toward ideas of objectivity and external reality.
An adherent or student of the philosophy of Protagoras.
Mid 17th century. From Protagoras (classical Latin Prōtagorās, ancient Greek Πρωταγόρας), the name of a Greek philosopher of the 5th cent. b.c. + -ean.