ἀνταποδίδωμι
Δελφῖνα νήχεσθαι διδάσκεις: ἐπὶ τῶν ἐν ἐκείνοις τινὰ παιδοτριβούντων, ἐν οἷς ἤσκηται → Teaching dolphins to swim: is applied to those who are teaching something among people who are already well versed in it
English (LSJ)
A give back, repay, tender in repayment or requital, Batr.186; ἀ. τὸ ὅμοιον, τὸἴσον, Hdt.1.18, Th.1.43; χάριν Pherecr. 2D.; τὴν ἴσην Arist.Rh.1379b7; ἀ. τροφεῖα Lys.6.49; ἀρετήν Th. 4.19; ὕβριν Plu.2.825c; τὰ αὐτὰ ἀ. react in the same way, Pl.Ti. 79e; of counter-arguments, Id.Prm.128d: abs., pay back, Th.3.40, Arist.Rh.1367a21. 2 take vengeance, LXX De.32.35, al., Ep.Rom.12.19. II assign as a balance, ἐναντίαν γένεσιν Pl.Phd. 71e. 2 make convertible, τὴν μεταφορὰν τὴν ἐκ τοῦ ἀνάλογον Arist. Rh.1407a15:—Pass., Demetr.Eloc.79. b Gramm., make to correspond, of correlatives (e.g. τοιοῦτος, οἷος), in Pass., A.D.Conj.254.19, Synt.54.5, al.; so of μέν . . δέ, Arist.Rh.1407a23, Demetr.Eloc.53, cf. Hermog.Id.1.4, al. 3 intr., answer to, correspond with, εἰ μὴ ἀνταποδιδοίη τὰ ἕτερα τοῖς ἑτέροις Pl.Phd.72a, cf. b; οὐκ ἀνταποδίδωσι τὸ ὅμοιον there is no similar correspondent, Arist.Mete.347b32, cf. IA 707b16, Ps.-Alex.Aphr.inSE192.14. 4 give back words, exchange 'tu quoque's', Pl Phdr.236c. III deliver in turn, τὸ σύνθημα X.Cyr.3.3.58 (Pass.); explain in turn, Pl.Ti.87c. IV give back a sound, of an echo, Plu.Sull.19; of troops, κραυγὴν ἀ. Id.Tim. 27.
German (Pape)
[Seite 244] (s. δίδωμι), dagegen wiedergeben, bes. was man erhalten hat, τὸ σύνθημα Xen. Cyr. 3, 3, 58; ὀφείλημα ἀνταποδοτέον Arist. Nicomach. 9, 2; vergelten, Batr. 187; τὸ ὅμοιον, Gleiches mit Gleichem vergelten, Her. 1, 18; νῦν ἀνταπόδοτε Thuc. 3, 40; τὸ ἴσον 1, 48; ἀνταποδοῦναι ἀρετήν 4, 19, d. i. sich zur Vergeltung brav zeigen, wie ὕβριν, Frevel mit Frevel vergelten, Plut. reip. ger. pr. 13 g. E.; vgl. Plat. Parm. 128 c Tim. 20 c; als entsprechend gegenüberstellen, ταῖς λύπαις καὶ ἡδοναῖς τὴν τούτων ἀντίστροφον ἕξιν Phil. 40 d; zurückwersen, reflektiren, vom Licht od. Schall, Plut. Syll. 32 Timol. 27 u. sonst, wie D. Hal. u. a. Sp. – Intrans., entsprechen, εἰ μὴ ἀεὶ ἀνταποδιδοίη τὰ ἕτερα τοῖς ἑτέροις γιγνόμενα Plat. Phaed. 72 a u. öfter Gramm.