Versatile stadium boxer whipped (12)
I believe the answer is:
ambidextrous
'versatile' is the definition.
(thesaurus)
'stadium boxer whipped' is the wordplay.
'whipped' indicates anagramming the letters.
'stadium'+'boxer'='stadiumboxer'
'stadiumboxer' with letters rearranged gives 'AMBIDEXTROUS'.
(Other definitions for ambidextrous that I've seen before include "Able to use both hands equally well" , "Highly adept" , "Using either hand" , "Using both hands" , "Equally skilful with either hand" .)