The most common and most likely answer to this crossword clue is the 4 letter word LOUT
I've seen this crossword clue in The Times
L
O
U
T
More clues leading to the result LOUT
Buddy explains!

The straight part
We know that "Churl" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case churl = lout.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 LOUT mean?
LOUT noun- A troublemaker, often violent; a rude violent person; a yob.
- A clownish, awkward fellow; a bumpkin.
- To treat as a lout or fool; to neglect; to disappoint.
- To bend, bow, stoop.