διαιτητής

A. arbitrator, umpire, Hdt. 5.95, Pl. Lg. 956c, etc.; τῆς γὰρ δίκης . . γίγνεταί μοι δ. Στράτων D. 21.83; δ. ὁ μέσος Arist. Pol. 1297a6; esp. at Athens, Id. Ath. 53, etc.

II. in later Law, = judex pedaneus, Cod.Just. 4.20.15, etc.