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
subs.
P. and V. ἰσθμός, ὁ. Shaped like an isthmus, adj.: P. ἰσθμώδης.