eleventh
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
or she shall learn even at the eleventh hour that 'tis labour lost to honour what is dead: ἢ γνώσεται γοῦν ἀλλὰ τηνικαῦθ' ὅτι πόνος περισσός ἐστι τἀν ᾍδου σέβειν (Soph., Antigone 779).