That man's involved in court case (5)
I believe the answer is:
chest
'case' is the definition.
(thesaurus)
'that man's involved in court' is the wordplay.
'that man' becomes 'hes' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'involved in' is an insertion indicator.
'court' becomes 'ct'.
'hes' placed into 'ct' is 'CHEST'.
Can you help me to learn more?
(Other definitions for chest that I've seen before include "Upper trunk" , "Bust" , "drawers in it!" , "Box or trunk" , "Box - breast" .)