Taunt policeman with face of granite (3)
I believe the answer is:
dig
'taunt' is the definition.
(thesaurus)
'policeman with face of granite' is the wordplay.
'policeman' becomes 'di' (detective inspector).
'with' says to put letters next to each other.
'face of' indicates taking the first letters.
The initial letter of 'granite' is 'g'.
'di'+'g'='DIG'
(Other definitions for dig that I've seen before include "A short archaeological excavation" , "Delve" , "Really like" , "Loosen, or remove earth" , "Go into" .)