The most common and most likely answer to this crossword clue is the 5 letter word CAMUS
I've seen this crossword clue in The Guardian
C
A
M
U
S
More clues leading to the result CAMUS
- Philosophical writer that’s across the pond on fenland river
- River Ouse’s outsides removed by thinker
- “No parking in university grounds” – he had plenty of absurd ideas
- Extract from Balzac amuses another French writer
- Educational setting devoid of pressure for French writer
- Eccentric American writer
- Climbing tree, he pondered the human condition
- French writer enthralled by electronica music
- Existentialist school grounds having no piano
Buddy explains!

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.