ἀπομείρομαι
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)
A distribute, αἶσαν Hes.Op.578. 2 Pass., to be parted from, Id.Th.801, Arat.522:—in each place with v.l. ἀπαμείρομαι (q.v.).