Sunup (noun)

1. The time of day when the sun rises.
2. The beginning of daylight or the start of a new day.

Origin:

From the word "sun" and "up".

Examples:

1. I always go for a run at sunup.
2. The birds start chirping at sunup.
3. The farmers were up early to start their day at sunup.
4. The beach was empty at sunup, but it got crowded as the day went on.
5. We planned our day trip to start at sunup to avoid the heat.