ἀμοιβαῖος
εἰς πέλαγος σπέρµα βαλεῖν καὶ γράµµατα γράψαι ἀµφότερος µόχθος τε κενὸς καὶ πρᾶξις ἄκαρπος → throwing seeds and writing letters at sea are both a vain and fruitless endeavor
English (LSJ)
ον, also α, ον,
A giving like for like, retributive, δεῖπνα Pi.O.1.39; retributive, νέμεσις, φόνος, AP10.123 (Aesop.), Opp.C.2.485. Adv. -ως alternately, Luc.Am.9. II interchanging, reciprocal, Emp.30.3; ἀ. βιβλία interchanged letters, Hdt.6.4; ἀ. χάρις exchange of favours, A.R.3.82 (but ἀ. εὐνή ambiguous (half-human, half-animal), 2.1241):—τὰ ἀ. dialogue in Trag., Pl.R.394b; of the responsion of choric odes, Plu.Pomp.48; ἀ. ἀοιδά Theoc.8.31, cf. Il. 1.604; answering as in dialogue, Sch.Ar.Pl.253,487.
German (Pape)
[Seite 127] α, ον (-βή), abwechselnd, wechselseitig, δεῖπνα Pind. Ol. 1, 39; βιβλία, gewechselte Briefe, Her. 6, 4; τὰ ἀμ., Wechselgespräche, Plat. Rep. III, 394 b; vom Wechselgesang, χορὸς εἰς τὰ ἀμ. συγκεκροτημένος Plut. Pomp. 48; ἀοιδή Theocr. 8, 31; aber Νέμεσις, vergeltend, Aesop. ep. (X, 123), wie χάριτεσβαῖαι Leon. Tar. 98 (VII, 657); sp. D. oft. – Adv. -βαίως, Luc. Amor. 9.