Whistle a hit? (4)
I believe the answer is:
blow
This clue is a double definition.
'whistle' is the first definition.
(thesaurus)
'a hit?' is the second definition.
(I've seen this before)
(Other definitions for blow that I've seen before include "Be windy; unlucky stroke" , "Sudden disappointment" , "haymaker, perhaps" , "Blast" , "Bang, wallop" .)