Workman excited over pieta (9)
I believe the answer is:
operative
'workman' is the definition.
(thesaurus)
'excited over pieta' is the wordplay.
'excited' is an anagram indicator.
'over'+'pieta'='overpieta'
'overpieta' with letters rearranged gives 'OPERATIVE'.
(Other definitions for operative that I've seen before include "Working (person)" , "Significant" , "Functioning; worker" , "desired effect" , "American detective" .)