Trial print; evidence (5)
I believe the answer is:
proof
I believe this is a double definition.
'trial print' is the first definition.
(I've seen this in another clue)
'evidence' is the second definition.
(evidence proves something)
(Other definitions for proof that I've seen before include "a writer may check" , "Body of evidence" , "Evidence that establishes the truth" , "to give a watertight case?" , "Author may have to check this" .)