ἐπωφελής
From LSJ
πρῶτον μὲν οὖν ὄστρεια παρὰ Νηρεῖ τινι ἰδὼν γέροντι φυκί ἠμφιεσμένα ἔλαβον ἐχίνους τ' ἐστὶ γὰρ προοίμιον δείπνου χαριέντως ταῦτα πεπρυτανευμένου → So first I spotted oysters wrapped in seaweed at the shop of some old Nereus, and sea urchins, which I bought; these were the appetizers for a delightfully managed dinner
English (LSJ)
ές,
A helpful, useful, Sever. Clyst.p.17 D., Poll.5.136, Cod.Just.1.2.17.1 ; ἡμῖν Hierocl.in CA11p.441M. Adv. -λῶς Poll.5.135, Vett. Val.165.18, Them.Or.21.252a,22.278c.
German (Pape)
[Seite 1016] ές, hülfreich, nützlich, Schol. Ar. Plut. 88. – Adv., Themist. u. a. Sp.