Group of crows (6)
I believe the answer is:
murder
'group of crows' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for murder that I've seen before include "Homicide (very noisy when blue)" , "Dispatch" , "a lot of crows" , "Unlawful premeditated killing" , "See 20" .)