twilight
From LSJ
τραχὺς ἐντεῦθεν μελάμπυγός τε τοῖς ἐχθροῖς ἅπασιν → he is a tough black-arse towards his enemies, he is a veritable Heracles towards his enemies
time just before dawn: P. and V. ὄρθρος, ὁ, P. τό περίορθρον.
darkness: Ar. and V. κνέφας, τό (also Xen.).