Medium that is in opposition to gangster is old-fashioned and primitive (8)
I believe the answer is:
medieval
'medium that is in opposition to gangster is old-fashioned and primitive' is the definition.
Both the definition and answer are adjectives. Perhaps they are linked in a way I don't understand?
'medium that is in opposition to gangster' is the wordplay.
'medium' becomes 'm' (as in UK clothing sizes).
'that' becomes 'edie' (I am not sure about this - if you are sure you should believe this answer much more).
'is in opposition to' becomes 'v' (abbreviation for versus).
'gangster' becomes 'al' (Al Capone).
'm'+'edie'+'v'+'al'='MEDIEVAL'
Can you help me to learn more?
(Other definitions for medieval that I've seen before include "Belonging to the Middle Ages" , "Relating to the Middle Ages" , "Am veiled in style of the middle ages" , "Of the middle ages, or really old-fashioned" , "Of an earlier period" .)