Don of "Get Smart" (5)
I believe the answer is:
adams
'don of get smart' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for adams that I've seen before include "Ansel --, US landscape photographer" , "Gaolers" , "Of untidy appearance" , "revolutionary leader" , "Richard --, Watership Down author" .)