The most common and most likely answer to this crossword clue is the 5 letter word SODOM
I've seen this crossword clue in Financial Times
S
O
D
O
M
More clues leading to the result SODOM
- Instant good advice to follow up in place of evil?
- Doom's spelt out for this place
- Place of depravity old bikers get upset over entering
- 29’s partner in bad mood after Howards End
- Some without first experience holding party to be a scene of depravity
- Biblical city like this, with kind of effect half erased
- 28 Going astray dooms wicked old city
- Scene of destruction over misdeeds initially
- Scene of depravity overlooking morals initially
- Lasso dominatrix holds in place of depravity
Buddy explains!

The straight part
We know that "29’s partner" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case 29’s partner = sodom.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.