Abbott-Smith Manual Greek Lexicon
ὅρκος (G3727)
11 ὅρκος , -ου, ὁ , [in LXX chiefly for שֶׁבַע , שִׁבְעָה and cogn. forms;] an oath : Mt 14:7 26:72 , Lk 1:73 , Ac 2:30 , He 6:16 , 17 , Ja 5:12 ; p1., Mt 5:33 (LXX) 14:9 , Mk 6:26 .†
G. Abbott-Smith, A Manual Greek Lexicon of the New Testament (1922) — public domain