Shut loudly (4)
I believe the answer is:
slam
'shut loudly' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for slam that I've seen before include "Hit hard" , "A grand one is 13 tricks" , "ambitious bid" , "Close noisily" , "Winning all (or all but one) of the tricks in bridge" .)