The most common and most likely answer to this crossword clue is the 3 letter word EVE
I've seen this crossword clue in The Times
E
V
E
More clues leading to the result EVE
- The day before still hasn’t finished
- The night before armistice, finally Victory in Europe
- Female bad, not half, ending in shame
- First lady entering the velodrome?
- Biblical character, drawn endlessly
- Woman in garden the day before Christmas?
- Girl’s uniform just too short
- Girl’s flat unfinished
- Woman undressed in garden the previous day
- Lady first appearing when it gets dark
Buddy explains!

The straight part
We know that "Lady first appearing/when it gets dark" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case lady first appearing/when it gets dark = eve.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 EVE mean?
EVE noun- The day or night before, usually used for holidays, such as Christmas Eve.
- Evening, night.
- The period of time when something is just about to happen or to be introduced