A European king's missing daughter's OK (6)
I believe the answer is:
agreed
'ok' is the definition.
(thesaurus)
'a european king's missing daughter's' is the wordplay.
I cannot quite see how this works, but
'a' is present in the answer.
'european' could be 'e' (abbreviation e.g. EU) and 'e' is present in the answer.
'daughter' could be 'd' and 'd' is present in the answer.
'king' could be 'gr' and 'gr' is present in the answer.
A single letter 'e' remains which might be clued in a way I don't see.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for agreed that I've seen before include "Accepted; tallied" , "That's right" , "Gave consent" , "acceptable" , "Saw eye to eye" .)