The most common and most likely answer to this crossword clue is the 8 letter word DAYBREAK
I've seen this crossword clue in Financial Times
D
A
Y
B
R
E
A
K
More clues leading to the result DAYBREAK
- Sat perhaps alongside Bill, entertaining Roger and Dawn
- Dawn’s daughter takes time off to tour Yarmouth
- Lighting-up time?
- Bakery ad broadcast first thing in the morning
- Let it dawn: holiday comes after 24 hours
- Dawn marking a 24-hour recess
- Bread, half cake and some yoghurt distributed at dawn
- Lifetime opportunity for widespread enlightenment
Buddy explains!

The straight part
We know that "Dawn" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case dawn = daybreak.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does DAYBREAK mean?
DAYBREAK noun- Dawn.