The most common and most likely answer to this crossword clue is the 5 plus 5 letter word STRIP JOINT
I've seen this crossword clue in The Times
S
T
R
I
P
J
O
I
N
T
More clues leading to the result STRIP JOINT
Buddy explains!

The straight part
We know that "seedy venue" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case seedy venue = strip joint.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.