δέον · deon — LSJ
that which is binding, needful, right, it be needful, good time, needful purposes, in case of need, secret service
neut. Subst., prop. part. of impers. δεῖ (q. v.):—that which is binding, needful, right, μᾶλλον τοῦ δ. X. Mem. 4.3.8; τὰ δ. Th. 1.22, etc.; οὐδὲν τῶν δ. πράττοντες Isoc. 3.25; πρὸ τοῦ δ. before it be needful, S. Ph. 891; ἐν δέοντι (sc. καιρῷ) in good time, E. Med. 1277, Plu. Cim. 17; ἐν τῷ δ. Hdt. 2.159; ἐς δέον ἐγεγόνεε Id. 1.119, cf. 186; ἐς δ. πάρεστι S. OT 1416, cf. Ant. 386; εἰς δ. λέγειν D. 4.14; εἰς τὸ δ. for needful purposes, or in case of need, ἐς τὸ δ. χρῆσθαι Hdt. 2.173: hence of secr