Criminal fined after king is stabbed (6)
I believe the answer is:
knifed
'is stabbed' is the definition.
(I've seen this before)
'criminal fined after king' is the wordplay.
'criminal' is an anagram indicator.
'after' says to put letters next to each other.
'king' becomes 'k'.
'fined' is an anagram of 'nifed'.
'nifed' after 'k' is 'KNIFED'.
(Other definitions for knifed that I've seen before include "deceived furtively" , "Cut" , "Stabbed with intent to harm or kill" .)