The most common and most likely answer to this crossword clue is the 5 letter word NIGHT
I've seen this crossword clue in The Times
N
I
G
H
T
More clues leading to the result NIGHT
- Almost all the booze knocked back in darkness
- Observation requiring switch in direction: it’s becoming dark
- Time out?
- It's almost time when I should retire
- It may be black chess piece
- Almost time for parting word
- Dark near end of street
- Close to - halfway there - death?
- Dark, curious thing
- Man’s heading off when it’s time to retire
Buddy explains!

The straight part
We know that "Time out?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case time out? = night.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 NIGHT mean?
NIGHT noun- The period between sunset and sunrise, when a location faces far away from the sun, thus when the sky is dark.
- (Astronomy) The period of darkness beginning at the end of evening astronomical twilight when the sun is 18 degrees below the horizon, and ending at the beginning of morning astronomical twilight.
- (Legal) Often defined in the legal system as beginning 30 minutes after sunset, and ending 30 minutes before sunrise.
- An evening or night spent at a particular activity.
- A night (and part of the days before and after it) spent in a place away from home, e.g. a hotel.
- Nightfall.
- Darkness (due to it being nighttime).
- A dark blue colour, midnight blue.
- A night's worth of competitions, generally one game.
- To spend a night (in a place), to overnight.
- Ellipsis of good night