The most common and most likely answer to this crossword clue is the 12 letter word BACKWOODSMAN
I've seen this crossword clue in Independent
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More clues leading to the result BACKWOODSMAN
Buddy explains!

The straight part
We know that "Uncouth fellow" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case uncouth fellow = backwoodsman.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 BACKWOODSMAN mean?
BACKWOODSMAN noun- A person who is acclimated to living in a forest area that is far removed from civilization or modern conveniences.
- An uncivilized person.
- (UK politics) A Peer who is seldom present in the House of Lords of the United Kingdom Parliament, who may be encouraged to attend when a very important vote is expected.