Pick-up Express for proof that one is not tolerated in court (7,8)
I believe the answer is:
hearsay evidence
'that one is not tolerated in court' is the definition.
'pick-up express for proof' is the wordplay.
'pick up' becomes 'hear' (hearing is a kind of picking up**).
'express' becomes 'say' (I've seen this before).
'for' is a charade indicator (letters next to each other).
'proof' becomes 'evidence' (I've seen this before).
'hear'+'say'+'evidence'='HEARSAY EVIDENCE'
(Another definition for hearsay evidence that I've seen is " Testimony not based on direct knowledge".)