Sort of lens to get nicked (6)
I believe the answer is:
stolen
'nicked' is the definition.
(I've seen this before)
'sort of lens to get' is the wordplay.
'sort of' is an anagram indicator.
'get' is an insertion indicator.
'lens' anagrammed gives 'slen'.
'slen' going around 'to' is 'STOLEN'.
(Other definitions for stolen that I've seen before include "Illegally taken" , "Taken without permission or payment" , "Pilfered" , "Taken by thieves" , "Filched" .)