ῥεμβός
From LSJ
γραμματική ἐστιν ἐμπειρία τῶν παρὰ ποιηταῖς τε καὶ συγγραφεῦσιν ὡς ἐπὶ τὸ πολὺ λεγομένων → grammar is a practical knowledge of the usage of poets and writers of prose
English (LSJ)
όν,
A roaming, roving, of a slave, prob. in BGU887.5, 16 (ii A.D.); of a lecturer on tour, Aristid.Or.33(51).28; ῥ. τῇ διανοίᾳ Antyll. ap. Orib.9.14.7; ψυχή M.Ant.2.17(v.l.).