Abbott-Smith Manual Greek Lexicon
γνόφος (G1105)
1 γνόφος (later form of δν- ), [in LXX for אָפֵל , עֲרָפֶל , etc. ;] darkness, gloom (including "an element of tempest," Tr., Syn. , §c): He 12:18 .† SYN. : ἀχλύς, ζόφος, σκότος (Tr., l.c.; DB , i, 457 a ).
G. Abbott-Smith, A Manual Greek Lexicon of the New Testament (1922) — public domain