Arrest grass in nick (7)

I believe the answer is:

copshop

I'm a little stuck... Click here to teach me more about this clue!

'nick' is the definition.
I don't know anything about this answer so I cannot tell whether it can be defined by this definition.

'arrest grass' is the wordplay.
'arrest' becomes 'cop' (synonyms).
'grass' becomes 'shop' (I've seen this before).
'cop'+'shop'='COPSHOP'

'in' is the link.

Can you help me to learn more?

(Other definitions for copshop that I've seen before include "police station" , "bluebottle, buzzing in this?" .)

I've seen this clue in The Telegraph.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.