ἵππαγρος
From LSJ
ἔνδον σκάπτε, ἔνδον ἡ πηγή τοῦ ἀγαθοῦ καί ἀεί ἀναβλύειν δυναμένη, ἐάν ἀεί σκάπτῃς → Dig within. Within is the wellspring of Good; and it is always ready to bubble up, if you just dig. | Look within. Within is the fountain of the good, and it will ever bubble up, if thou wilt ever dig.
English (LSJ)
ὁ,= ἵππος ἄγριος,
A wild horse, Opp.C.3.252.
German (Pape)
[Seite 1257] ὁ, das wilde Pferd, Opp. Cyn. 3, 252.