Court department turns up record and reveals paper's source (4,4)
I believe the answer is:
wood pulp
'paper's source' is the definition.
(paper is made from wood pulp)
'court department turns up record' is the wordplay.
'court' becomes 'woo' (synonyms).
'department' becomes 'd' (abbreviation eg in MOD Ministry of Defence).
'turns' shows that the letters should be reversed in order.
'record' becomes 'lp' (L-P is an example).
'up' in reverse letter order is 'pu'.
'woo'+'d'+'pu'+'lp'='WOOD-PULP'
'and reveals' is the link.
(Another definition for wood pulp that I've seen is " Material from which paper is made".)