Examined (6)
'examined' is the definition.
('test' can be a synonym of 'examine')
This is all the clue.
(Other definitions for tested that I've seen before include "Measured for quality or reliability" , "Trialled" , "Proven" , "Put through a trial" , "Probed or analysed" .)
'examined' is the definition.
('study' can be a synonym of 'examine')
This is all the clue.
(Other definitions for studied that I've seen before include "Examined" , "Considered, learnt about" , "Well-considered" , "deliberate" , "Looked at closely" .)
'examined' is the definition.
(checking is a kind of examining)
This is all the clue.
(Other definitions for checked that I've seen before include "Patterned with alternating squares of colour" , "Restrained" , "Verified, passed inspection" .)