Fortunate ancient human, receiving King (5)
I believe the answer is:
lucky
'fortunate' is the definition.
('lucky' can be similar in meaning to 'fortunate')
'ancient human receiving king' is the wordplay.
'ancient human' becomes 'lucy' (name given to ancient skeleton discovered in 1974).
'receiving' indicates putting letters inside.
'king' becomes 'k'.
'lucy' enclosing 'k' is 'LUCKY'.
(Other definitions for lucky that I've seen before include "Bringing good fortune" , "by chance" , "Blessed with good fortune" , "Game where prizes are picked from a tub" , "'It is better to be born . . . . . than rich'" .)