Group competently curbs rising disorder (8)
I believe the answer is:
assembly
'group competently' is the definition.
'assembly' can be an answer for 'group' (I've seen this before). I'm not sure about the 'competently' bit.
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for assembly that I've seen before include "Group of people gathered together for a purpose" , "Meeting; fabrication" , "Legislative body" , "Gathering, congretation 98)" , "Diet, perhaps" .)