Namely, shop involved in wickedness getting shut finally (9)
I believe the answer is:
videlicet
'namely' is the definition.
(I know that namely can be written as videlicet)
'shop involved in wickedness getting shut finally' is the wordplay.
'shop' becomes 'deli' (deli is a kind of shop).
'involved in' means one lot of letters goes inside another.
'wickedness' becomes 'vice' (I've seen this before).
'getting' says to put letters next to each other.
'finally' says to take the final letters.
The final letter of 'shut' is 't'.
'deli' put inside 'vice' is 'videlice'.
'videlice'+'t'='VIDELICET'
(Other definitions for videlicet that I've seen before include "Viz. in full, namely" , "that is to say" , "to wit" , "in other words" .)