The most common and most likely answer to this crossword clue is the 9 plus 4 letter word ONE-HORSE TOWN
I've seen this crossword clue in The Guardian
O
N
E
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H
O
R
S
E
T
O
W
N
More clues leading to the result ONE-HORSE TOWN
Buddy explains!
The straight part
We know that "a dull place to live" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case a dull place to live = one-horse town.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.