Skilfully kept disorder returning to meeting (8)
I believe the answer is:
assembly
'to meeting' is the definition.
(I've seen this before)
'skilfully kept disorder returning' is the wordplay.
'skilfully' becomes 'ably'.
'kept' indicates putting letters inside.
'disorder' becomes 'mess' (messing is a kind of disordering).
'returning' says the letters should be written backwards.
'mess' in reverse letter order is 'ssem'.
'ably' enclosing 'ssem' is 'ASSEMBLY'.
(Other definitions for assembly that I've seen before include "Diet, perhaps" , "A gathering for formal meeting" , "Meeting; fabrication" , "This line is a sequence of machines and workers" , "Gathering of people or fitting of parts together" .)