A.fort or stronghold placed on the enemy's frontier, v.l. in Id.8.95, cf. X.HG5.1.2 ; τινί or ἐπί τινα against one, “κατασκευάζειν ὑμῖν ἐ. τὴν Εὔβοιαν” D.8.66 ; “ἐπὶ τὴν Ἀττικήν” Id.18.71 ; “κατὰ τῆς πόλεως” D.H.3.43 : c. gen., ἔχουσι τοσαῦτ᾽ ἐ. τῆς αὑτοῦ χώρας holding so many fortresses which command his country, D.4.5.
2. metaph., τῆς αὑτῆς ἀρχῆς ἐ. πρὸς τὸ μηδ᾽ ὁτιοῦν παρακινεῖν a barrier or obstacle to.., Id.15.12 ; “ὥσπερ ἐ. τοῖς υἱοῖς κατάγει τὸν Ἀντίπατρον” J.BJ1.23.1 ; τὴν φιλοσοφίαν ἐ. τῶν νόμων a barrier against, or a bulwark in defence of, the laws, Alcid. ap. Arist.Rh.1406b11 ; ἐ. τῶν ἀνθρωπίνων παθῶν “ἡ ποιητικὴ καθέστηκεν” S.E.M.1.298.