Lawyer's document with shortened ceremony (4)
I believe the answer is:
writ
'lawyer's document' is the definition.
(I've seen this in another clue)
'with shortened ceremony' is the wordplay.
'with' becomes 'w' (abbreviation).
'shortened' means to remove the last letter.
'ceremony' becomes 'rite' (rite is a kind of ceremony).
'rite' with its last letter taken away is 'rit'.
'w'+'rit'='WRIT'
(Other definitions for writ that I've seen before include "Legal document, usually served" , "Legal document issued by an officer of the court" , "Legal order in writing" , "Legal or formal document" , "Subpoena" .)