Canny way to quieten rude audiences (6)
I believe the answer is:
shrewd
'canny' is the definition.
(I've seen this in another clue)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for shrewd that I've seen before include "Clever, having sound judgement" , "keen" , "... knowing" , "Astute in business" , "Astute or crafty" .)