Who had wrong seat on jumbo? (6)
I believe the answer is:
howdah
'seat on jumbo?' is the definition.
(I've seen this before)
'who had wrong' is the wordplay.
'wrong' indicates anagramming the letters.
'who'+'had'='whohad'
'whohad' with letters rearranged gives 'HOWDAH'.
(Other definitions for howdah that I've seen before include "Seat on an elephant's back" , "Seat for passengers on the back of an elephant" , "seat on Jumbo" , "Elephant rider's seat" , "top seat?" .)