A second chance to speak in trial (5)
I believe the answer is:
assay
'trial' is the definition.
(thesaurus)
'a second chance to speak in' is the wordplay.
'second' becomes 's' (common abbreviation).
'chance to speak' becomes 'say' (I've seen this before).
'in' indicates putting letters inside.
's' placed inside 'say' is 'ssay'.
'a'+'ssay'='ASSAY'
(Other definitions for assay that I've seen before include "Test (a metal or ore)" , "Test ore for value" , "Test purity of precious metal" , "Evaluate" , "Test the purity of metals" .)