ὀρθοέπεια
From LSJ
λύχνον μεθ' ἡμέραν ἅψας περιῄει λέγων ἄνθρωπον ζητῶ → he lit a lamp in broad daylight and said, as he went about, I am looking for a man
English (LSJ)
ἡ,
A correctness of diction, Democr.20a, Pl.Phdr.267c, Phld.Rh.1.191 S., D.H.Dem.26, Quint.1.6.20.
German (Pape)
[Seite 374] ἡ, die grade, richtige Aussprache (recta locutio, Quint. 1, 6); Plat. Phaedr. 267 c; D. Hal. de vi Dem. 26. Diese grammatische Lehre behandelte Protagoras, Spengel artium scriptores p. 40 ff.