μονόστεος
From LSJ
ἔνδον σκάπτε, ἔνδον ἡ πηγὴ τοῦ ἀγαθοῦ καὶ ἀεὶ ἀναβλύειν δυναμένη, ἐὰν ἀεὶ 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)
ον,
A consisting of one bone, κρανίον Arist.HA516a16; αὐχήν Id.PA686a21.