ἀντιχρηματίζομαι
From LSJ
ἀλλ' ἦν ἅπαντα τεταγμένα νόμων ἐπιταγαῖς → but all their acts were regulated by prescriptions set forth in laws
English (LSJ)
A transact business instead of another, PFlor.382.59 (iii A.D.).
Spanish (DGE)
actuar en nombre de otro, representar, PMich.529ue.49 (III d.C.), cf. PFlor.382.59 (III d.C.).