ἱππόκρημνος
From LSJ
Εὐφήμει, ὦ ἄνθρωπε· ἁσμενέστατα μέντοι αὐτὸ ἀπέφυγον, ὥσπερ λυττῶντά τινα καὶ ἄγριον δεσπότην ἀποδράς → Hush, man, most gladly have I escaped this thing you talk of, as if I had run away from a raging and savage beast of a master
English (LSJ)
ον,
A tremendously steep, ἱ. ῥῆμα a neck-breaking word, Ar.Ra. 929.