Clumsy former spouse in Pinter play (8)
I believe the answer is:
inexpert
'clumsy' is the definition.
(I've seen this before)
'former spouse in pinter play' is the wordplay.
'former spouse' becomes 'ex'.
'in' is an insertion indicator.
'play' indicates an anagram.
'pinter' anagrammed gives 'inpert'.
'ex' placed within 'inpert' is 'INEXPERT'.
(Other definitions for inexpert that I've seen before include "Lacking skill or knowledge" , "Green" , "Bumbling" , "not good enough" , "with little skill" .)