ὑπερθεματισμός
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)
ὁ,
A overbidding, Gloss., Charis. p.553K.
German (Pape)
[Seite 1196] ὁ, das Ueberbieten, Sp.