ἐμποδὼν γίγνομαι
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)
Greek > English (Woodhouse)
hinder, be a bar to, be a barrier to, be a check to, be a hindrance to, be an impediment to, be an interruption to, be an obstacle to, be an obstacle