The most common and most likely answer to this crossword clue is the 4 letter word LEST
L
E
S
T
More clues leading to the result LEST
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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 LEST mean?
LEST conjunction- For fear that; that not; in order to prevent something from happening; in case.
- (after certain expressions denoting fear or apprehension) that (without the negative particle; introduces the reason for an emotion.)