effective
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 > Greek (Woodhouse)
adjective
hitting the mark: P. επιτυχής.
accomplish its object: P. and V. δραστήριος, V. πρακτήριος.
fit for action: P. ἐνεργός, δυνατός.
authoritative: P. and V. κύριος.
Latin > English
effective ADV :: effectively; productively