Crack constabulary is inspiring (4)
I believe the answer is:
stab
'crack' is the definition.
(I've seen this in another clue)
'constabulary is inspiring' is the wordplay.
'is inspiring' says the answer is hidden in the clue (the clue has breathed in or 'inspired' the answer).
'STAB' is hidden within 'constabulary'.
(Other definitions for stab that I've seen before include "Impale; attempt" , "Knife thrust; attempt" , "pink" , "Go" , "Pierce with something pointed" .)