Short legal memorandum (5)
I believe the answer is:
brief
This clue is a double definition.
'short' is the first definition.
(synonyms)
'legal memorandum' is the second definition.
(I've seen this in another clue)
(Other definitions for brief that I've seen before include "Document stating the facts of a legal case" , "Fibre (anag.)" , "Case given to a barrister" , "scanty" , "Provide someone with the facts of the case" .)