ἀβακής
From LSJ
θοῦ, Κύριε, φυλακὴν τῷ στόµατί µου καὶ θύραν περιοχῆς περὶ τὰ χείλη µου → set a guard over my mouth, Lord; keep watch over the door of my lips | set a guard, O Lord, over my mouth; keep watch over the door of my lips (Psalm 140:3, Septuagint version)
English (LSJ)
ές, (βάζω)
A speechless: hence, calm, gentle, ἀβάκην (Aeol. acc.) τὰν φρέν' ἔχω Sapph.72. Adv. -κέως, εὕδοντι Poet. ap. EM2.57:—also ἀβακήμων Hsch., ἄβαξ Lex.Rhet.ap.Eust.1494.64.