Fact prosecutor put before corporation (5)
I believe the answer is:
datum
'fact' is the definition.
(thesaurus)
'prosecutor put before corporation' is the wordplay.
'prosecutor' becomes 'da' (D.A. is an example).
'put before' is a charade indicator (letters next to each other).
'corporation' becomes 'tum' (I've seen this before).
'da'+'tum'='DATUM'
(Other definitions for datum that I've seen before include "bit of info" , "Premiss, thing taken for granted" , "Single piece of information" , "Bit of dope" , "Unit of dope" .)