Dictionary entry

ἐξαίφνης

G. Abbott-Smith's A Manual Greek Lexicon of the New Testament

ἐξ-αίφνης (WH, ἐξέφνης, exc. Ac 22:6; v. App., p. 151, and cf. M, Pr., 35),adv.

(< ἄφνω), [in LXX chiefly for פִתְאׄם;]

suddenlyMk 13:36, Lk 2:139:39, Ac 9:322:6.†