The most common and most likely answer to this crossword clue is the 7 plus 3 letter word COUNTRY PUB
I've seen this crossword clue in The Guardian
C
O
U
N
T
R
Y
P
U
B
Buddy explains!
The straight part
We know that "bar out of town" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case bar out of town = country pub.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.