ἀγαστῶς
From LSJ
Ζῆν οὐκ ἄξιος, ὅτῳ μηδὲ εἷς ἐστι χρηστὸς φίλος → Life is not worth living if you do not have at least one friend.
French (Bailly abrégé)
adv.
admirablement.
Étymologie: ἀγαστός.
Russian (Dvoretsky)
ἀγαστῶς: замечательно, изумительно (πρᾶξαι Xen.).