Angry about king’s coursing (9)
I believe the answer is:
streaming
'coursing' is the definition.
(streaming is a kind of coursing)
'angry about king's' is the wordplay.
I cannot really see how this works, but
'about' could be 'rea' (I've seen this in other clues) and 'rea' is found within the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for streaming that I've seen before include "going in large quantities" , "Way of classifying the children" , "moving en masse" .)