King having coronation (8)
I believe the answer is:
crowning
'coronation' is the definition.
(I've seen this before)
'king having' is the wordplay.
'king' becomes 'CR' (short for Carolus Rex, King Charles in Latin).
'having' becomes 'owning' ('own' can be a synonym of 'have').
'cr'+'owning'='CROWNING'
(Other definitions for crowning that I've seen before include "Coronation" , "Topping" .)