Fall holding good after a king’s put on trial (7)
I believe the answer is:
arraign
'put on trial' is the definition.
(I've seen this before)
'fall holding good after a king's' is the wordplay.
'fall' becomes 'rain' (raining is a kind of falling).
'holding' indicates putting letters inside.
'good' becomes 'g' (abbreviation).
'after' is a charade indicator (letters next to each other).
'king' becomes 'R' (abbreviation for rex, king in Latin).
'rain' going around 'g' is 'raign'.
'a'+'r'='ar'
'raign' put after 'ar' is 'ARRAIGN'.
(Other definitions for arraign that I've seen before include "put on a charge" , "Bring to trial" , "Indict, accuse" , "Bring to court to answer a charge" , "Accuse publicly" .)