Hammer time! (4)
I believe the answer is:
beat
This clue is a double definition.
'hammer' is the first definition.
(thesaurus)
'time' is the second definition.
(beat is a kind of time)
(Other definitions for beat that I've seen before include "Master" , "Strike; rhythm" , "Worst round" , "Tan" , "Get the better of in competition" .)