ἀμφιλύκη
From LSJ
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)
νύξ, ἡ,
A = λοκόφως, half light, morning twilight, Il 7.433; without νύξ, A.R.2.671, Opp.C.1.135, AP5.280 (Paul. Sil.), Lyd.Ost. 65. (No masc. is found.)
German (Pape)
[Seite 140] νύξ (s. λυκόφως), Morgendämmerung, der grauende Morgen, Hom. einmal, Iliad. 7, 433 Scholl. Ariston. ἡ διπλῆ, ὅτι ἅπαξ μόνον ἐνταῦθα τῇ λέξει κέχρηται; – ohne νύξ Ap. Rh. 2, 671; – Agath. 78 (VII, 583) τρισσὴ δ' ἀμφιλύκη δρόμον ἤνυσεν.