ἰδιωτισμός
From LSJ
μὴ κακὸν εὖ ἔρξῃς· σπείρειν ἴσον ἔστ' ἐνὶ πόντῳ → do no good to a bad man; it is like sowing in the sea
English (LSJ)
ὁ,
A way or fashion of a common person, Epict.Ench.33.6, S.E.M.1.67, Dam.Isid.223; in language, homely, vulgar phrase, Phld.Po.2.71, Longin.31.1, D.L.7.59. 2 Rhet., argumentum ad hominem, usu. in the form of a hypothetical question, Rufin.Fig.10.