Abbott-Smith Manual Greek Lexicon
ἐπανάγκης (G1876)
1 * ἐπανάγκης , -ες ( ἀνάγκη ), only in neut.; ἐπάναγκες (sc. ἐστί ), it is compulsory, necessary . As adv., of necessity : Ac 15:28 .†
G. Abbott-Smith, A Manual Greek Lexicon of the New Testament (1922) — public domain