ὄρθροςórthros

Same root

• ὄροςóros · G3735perhaps akin to G142 (αἴρω); compare G3733 (ὄρνις)); a mountain (as lifting itself above the plain)
• ὀρθρινόςorthrinós · G3720relating to the dawn, i.e. matutinal (as an epithet of Venus, especially brilliant in the early day)
• ὀρθρίζωorthrízō · G3719to use the dawn, i.e. (by implication) to repair betimes
• ὄρθριοςórthrios · G3721in the dawn, i.e. up at day-break

Where it appears

Appears 2 times in the Bible.

• Luke 24:1 But very early on Sunday morning the women went to the tomb, taking the spices they had prepared.
• Acts 5:21 So at daybreak the apostles entered the Temple, as they were told, and immediately began teaching. When the high priest and his officials arrived, they convened the high council—the full assembly of the elders of Israel. Then they sent for the apostles to be brought from the jail for trial.