An order to attend court (8)
I believe the answer is:
subpoena
'an order to attend court' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for subpoena that I've seen before include "Writ ordering court apperarance about bean soup" , "Hearing reminder" , "Writ ordering someone to attend a court" , "Order to appear in court" , "Writ compelling attendance in court" .)