Expect too much of European King in public (9)
I believe the answer is:
overexert
'expect too much' is the definition.
I can't judge whether this defines the answer.
'european king in public' is the wordplay.
'european' becomes 'E' (abbreviation e.g. EU).
'king' becomes 'rex' ('king' in Latin).
'in' is an insertion indicator.
'public' becomes 'overt' (both can mean well-known or unconcealed).
'e'+'rex'='erex'
'erex' going within 'overt' is 'OVEREXERT'.
'of' is the link.
Can you help me to learn more?
(Other definitions for overexert that I've seen before include "work too hard" , "Make too much effort" , "strain" , "use too much" , "exercise unduly?" .)