καθαριεύω
From LSJ
καὶ κεραμεὺς κεραμεῖ κοτέει καὶ τέκτονι τέκτων, καὶ πτωχὸς πτωχῷ φθονέει καὶ ἀοιδὸς ἀοιδῷ → and potter is ill-disposed to potter, and carpenter to carpenter, and the beggar is envious of the beggar, the singer of the singer
English (LSJ)
A to be kaqa/rios, in Med., Alex.Aphr. Pr.2.53. II = καθαρεύω 3, Hdn.Gr. ap. Choerob.in Theod.1.232, Theognost.Can.28, etc.
German (Pape)
[Seite 1281] dasselbe, Sp.; auch vom Styl, Gramm.