The most common and most likely answer to this crossword clue is the 5 letter word DETER
I've seen this crossword clue in The Times
D
E
T
E
R
More clues leading to the result DETER
- Seeker of reduced fare, not one to get put off
- Put off time to cut grass back
- Put off find
- Prevent gent leaving cleaning fluid
- Discourage fellow taking daughter for piano
- A little time inside does perhaps discourage
- Consumer who's cutting back leaves island, getting put off
- . Stop cleaner hiding man
- Discourage careful eater, second to quit
- Time inside does maybe discourage
Buddy explains!

The straight part
We know that "Prevent" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case prevent = deter.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 DETER mean?
DETER verb- To prevent something from happening.
- To persuade someone not to do something; to discourage.
- To distract someone from something.