Experiments with matches (5)
I believe the answer is:
tests
This clue is a double definition.
'experiments with' is the first definition.
('test' can be a synonym of 'experiment with')
'matches' is the second definition.
(I have seen 'International matches ' mean 'tests' so perhaps 'matches' could also mean 'tests')
(Other definitions for tests that I've seen before include "Trials, exams" , "Puts to proof at cricket matches" , "Trials to see if something works" , "Major cricket matches" , "Trials -- tribulations" .)