Trials (5)
I believe the answer is:
tests
'trials' is the definition.
('test' can be a synonym of 'trial')
This is all the clue.
(Other definitions for tests that I've seen before include "Trials -- tribulations" , "Trials for cricketers" , "Trials to see if something works" , "Tries out" , "Puts to proof at cricket matches" .)