Natural inclination (4)
I believe the answer is:
bent
'natural inclination' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for bent that I've seen before include "Twisted - corrupt" , "Dodgy" , "Slang for dishonest or crooked" , "Crooked; grass" , "Crooked - penchant" .)