Trial: a time to persuade (7)
I believe the answer is:
attempt
'trial' is the definition.
(thesaurus)
'a time to persuade' is the wordplay.
'time' becomes 't'.
'to persuade' becomes 'tempt' (tempting is a kind of persuading).
'a'+'t'+'tempt'='ATTEMPT'
(Other definitions for attempt that I've seen before include "Try, make an effort" , "Shot" , "Stab" , "bid to kill someone" , "Essay" .)