Novice? One missing out with exploitative type in pocket (7)
I believe the answer is:
trouser
'pocket' is the definition.
(both can mean to steal or take)
'novice? one missing out with exploitative type' is the wordplay.
'novice?' becomes 'tiro' (synonyms).
'one' becomes 'i' (Roman numeral).
'missing out' is a deletion indicator.
'with exploitative type' becomes 'user' (I am not sure about this - if you are sure you should believe this answer much more).
'tiro' with 'i' taken away is 'tro'.
'tro'+'user'='TROUSER'
'in' is the link.
(Other definitions for trouser that I've seen before include "Pocket (something)" , "Pocket (slang)" , "For oneself" , "Our rest (anag)" , "Appropriate" .)