γραμμάτιον
From LSJ
Ῥῦσέ με δεινῶν νοσημάτων, ἱερώτατε, ἱερωσύνην συναρμόσας ἐν χαρᾷ και ἐπιστήμης τὸ πολύτιμον κεφάλαιον → Deliver me from grievous afflictions, most holy one, joining sanctity together in joy with the precious fountainhead of knowledge
English (LSJ)
τό, Dim. of γράμμα, Luc.Merc.Cond.36. II = γραμματεῖον, bond, contract, POxy.71.5 (iv A. D.).