Reason to take a case round to the central court (5)
I believe the answer is:
cause
'reason' is the definition.
(I've seen this before)
'a case round to the central court' is the wordplay.
'round' indicates putting letters inside.
'to the central' indicates the central letters.
The middle of 'court' is 'u'.
'case' enclosing 'u' is 'CAUSE'.
'to take' acts as a link.
(Other definitions for cause that I've seen before include "Reason; belief" , "Producer of an effect" , "Grounds" , "It brings about an effect" , "Genesis" .)