Stupid duke at the rear (4)

I believe the answer is:

daft

'stupid' is the definition.
(thesaurus)

'duke at the rear' is the wordplay.
'duke' becomes 'd'.
'at the rear' becomes 'aft' (I've seen this before).
'd'+'aft'='DAFT'

(Other definitions for daft that I've seen before include "Stupid" , "Informally silly or crazy" , "Half-witted" , "'---- as a brush': dotty" , "Barmy, crackers" .)

I've seen this clue in The Telegraph.

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