The most common and most likely answer to this crossword clue is the 9 letter word PRONENESS
I've seen this crossword clue in The Guardian
P
R
O
N
E
N
E
S
S
Buddy explains!
The straight part
We know that "Bent" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case bent = proneness.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 PRONENESS mean?
PRONENESS noun- The quality or state of being prone, or of bending downward.
- The state of lying with the face down.
- Descent; declivity.
- Inclination of mind, heart, or temper; propension; disposition.