Fortunate girl, visited by king (5)
I believe the answer is:
lucky
'fortunate' is the definition.
(similar in meaning)
'girl visited by king' is the wordplay.
'girl' becomes 'lucy' (girl's name).
'visited by' is an insertion indicator.
'king' becomes 'K' (abbreviation for king in chess).
'lucy' placed around 'k' is 'LUCKY'.
(Other definitions for lucky that I've seen before include "Serendipitous" , "having the rub of the green?" , "Auspicious" , "'It is better to be born . . . . . than rich'" , "by chance" .)