Archaically penned court order (4)
I believe the answer is:
This clue is a double definition.
'archaically penned' is the first definition.
(archaic form of 'written' ie 'penned')
'court order' is the second definition.
(I've seen this before)
(Other definitions for writ that I've seen before include "Legal document issued by an officer of the court" , "Court instrument" , "Legal document, usually served" , "It may be served" , "court paper" .)