στυφνός

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

Source

German (Pape)

[Seite 960] = στρυφνός, zw.