Abbott-Smith Manual Greek Lexicon
ὄρθριος (G3721)
1 ὄρθριος , -α, -ον ( ὄρθρος ), [in LXX: I Ki 28:14 , Jb 29:7 , III Mac 5:10 , 23 *;] early , in the early morning : Lk 24:22 , Rec. (v.s. ὀρθρινός ).†
G. Abbott-Smith, A Manual Greek Lexicon of the New Testament (1922) — public domain