Old king hides unexpected death of spiritual mentor (9)
I believe the answer is:
godfather
'spiritual mentor' is the definition.
The answer and definition can be both people as well as being singular nouns.
Maybe there's an association between them I don't understand?
'old king hides unexpected death of' is the wordplay.
'old king' becomes 'GR' (Georgius Rex, Latin for King George).
'hides' is an insertion indicator.
'unexpected' indicates anagramming the letters.
'death'+'of'='deathof'
'deathof' is an anagram of 'odfathe'.
'gr' enclosing 'odfathe' is 'GODFATHER'.
Can you help me to learn more?
(Other definitions for godfather that I've seen before include "He's a sponsor at Baptism" , "Mafia boss" , "Mafia head" , "Mafia chief or spiritual parent" , "gang boss" .)