3986 ὄρθρος (orthros), ου (ou), ὁ (ho): n.masc.; ≡ Str 3722—1. LN 67.187 early morning (Lk 24:1; Ac 5:21+; Jn 8:2 v.r.), for another focus, see next; 2. LN 67.73 daybreak dawn, for verses and another focus, see prior
James Swanson, Dictionary of Biblical Languages with Semantic Domains: Greek (New Testament) (Oak Harbor: Logos Research Systems, Inc., 1997).
DBL-G indicates that orthros is a "variant reading", but gives no further detail. NET notes don't mention this issue. Anyone have anything that might shed light on what is being indicated here?
On a different note, the "another focus" between "early morning" and "daybreak/dawn" seems like the difference between "big" and "large".