The most common and most likely answer to this crossword clue is the 5 letter word PANIC
I've seen this crossword clue in The Times
P
A
N
I
C
More clues leading to the result PANIC
- Fear of god?
- Criticise one Conservative creating alarm
- Lose one’s bottle, being a grass!
- Anxiety relating to certain countries that's not his
- I doze, sitting up with cold fear
- Lose one's nerve parking? I can, unfortunately
- Latin-American in USA cutting his grass
- Dread man losing his head during film
- Confused rush and grass
- Woke clutching auntie, oddly, in fear
Buddy explains!

The straight part
We know that "fear" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case fear = panic.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 PANIC mean?
PANIC noun- Overpowering fright, often affecting groups of people or animals.
- Rapid reduction in asset prices due to broad efforts to raise cash in anticipation of continuing decline in asset prices.
- A kernel panic or system crash.
- To feel overwhelming fear.
- To cause somebody to panic.
- (by extension) To crash.
- (by extension) To cause the system to crash.
- Pertaining to the god Pan.
- Of fear, fright etc: sudden or overwhelming (attributed by the ancient Greeks to the influence of Pan).
- A plant of the genus Panicum.