Testing out in court (6)
I believe the answer is:
trying
'testing' is the definition.
('try' can be a synonym of 'test')
'in court' is the wordplay.
I cannot really see how this works, but
'in' is within the answer.
This explanation may well be incorrect...
'out' is the link.
Can you help me to learn more?
(Other definitions for trying that I've seen before include "Difficult - hearing" , "Making an effort - it's irritating" , "occupation of Oliver Wendell Holmes Jnr" , "Difficult - annoying" , "Bothersome" .)