EXQRA in James 4:4

Comments follow from Louw and Nida's Greek Lexicon:

"ἔχθρα, ας [feminine]: a state of enmity with someone-'enmity, being an enemy of.' οὐκ οἴδατε ὅτι ἡ φιλία τοῦ κόσμου ἔχθρα τοῦ θεοῦ ἐστίν: 'do you not know that being friendly with the world means being at enmity with God?' Jas 4:4."

From Liddell-Scott:

ἔχθρ-α , Ion. ἔχθρη , ἡ,
A. hatred, enmity, Hdt.5.81, Pi.P.4.145, etc.: in philos. sense, = νεῖκος 1.5, Plot.3.2.2; ἔ. τινός hatred for, enmity to one, Antipho 2.4.1, Th.3.10; “κατ᾽ ἔχθραν τινός” Ar.Pax 133; “ἔ. ἔς τινα” Hdt.1.5, Th.2.68; “εἴς θεόν” Ep.Rom.8.7; “πρός τινα” A.Pr.491 (pl.), Th.2.68; δι᾽ ἔχθρας μολεῖν, ἀφῖχθαί τινι, to be at feud with one, E.Ph. 479, Hipp.1164; “δι᾽ ἔχθρας οὐδετέρῳ γενήσομαι” Ar.Ra.1412; “εἰς ἔ. βάλλειν τινά” A.Pr.390; “εἰς ἔ. ἐλθεῖν” D.21.62; “καταστῆσαί τινας εἰς ἔχθραν τῷ δήμῳ” X.HG3.5.9; “πολλὴν εἰς ἔχθραν ἀλλήλοις καὶ πολλῶν πέρι καθίστανται” Pl.Plt.307d, cf. Isoc.9.67; πρὸς ἔχθραν from personal enmity, D.18.141; ἔ. συμβάλλειν, συνάπτειν τινί, to engage in hostility with . . , E.Med.45, Heracl.459; “ἔ. τισὶν ἄρασθαι” D.21.132; “καταλλάσσεσθαι τὰς ἔ.” Hdt.7.145; “λύσασαν ἔ. τὴν πάρος” E.Tr.50; “τὰς μεγάλας ἔ. διαλύεσθαι” Th.4.19; “πρὸς ἀλλήλους ἔ. ἀνείλοντο” Is.1.9; “διαλλαχθῆναι τῆς ἔ.” And.2.26: prov., Ἐμπεδοκλέους ἔ., of undying hatred, Lys. Fr.261 S.