This root form (lemma) is used in 2 different forms in the NT: ὄρθρον (AMS), ὄρθρου (GMS).
It is glossed in 1 way: ‘dawn’.
OET LUKE 24:1 Greek word=ὄρθρου (orthrou) Morphology=GMS English gloss=‘dawn’ SR GNT LUKE 24:1 word 8
OET ACTS 5:21 Greek word=ὄρθρον (orthron) Morphology=AMS English gloss=‘dawn’ SR GNT ACTS 5:21 word 6