Mister, a dude, contrived to get something much wanted (11)
I believe the answer is:
desideratum
'something much wanted' is the definition.
(I've seen this before)
'mister a dude contrived' is the wordplay.
'contrived' indicates anagramming the letters.
'mister'+'a'+'dude'='misteradude'
'misteradude' anagrammed gives 'DESIDERATUM'.
'to get' is the link.
(Other definitions for desideratum that I've seen before include "Something much wanted" , "As requirement" , "Something needed or wanted" , "Something much needed" , "Essential" .)