Checked, examined (6)
I believe the answer is:
tested
This clue is a double definition.
'checked' is the first definition.
('test' can be a synonym of 'check')
'examined' is the second definition.
(testing is a kind of examining)
(Other definitions for tested that I've seen before include "Proven" , "In repose" , "Subjected to examination, put through paces" , "Examined for quality or reliability" , "critically examined" .)