Unlawful stocktaking? (8)
I believe the answer is:
rustling
'unlawful stocktaking?' is the definition.
Although both the answer and definition are singular nouns, I don't see how one could define the other.
This is the entire clue.
Can you help me to learn more?
(Other definitions for rustling that I've seen before include "Stealing cattle" , "Light noise, like leaves blowing in the wind" , "Cattle theft" , "Stealing (livestock)" , "Gentle sound" .)