A throne prepared for someone else (7)
I believe the answer is:
another
'someone else' is the definition.
(I've seen this before)
'a throne prepared' is the wordplay.
'prepared' indicates anagramming the letters.
'throne' anagrammed gives 'nother'.
'a'+'nother'='ANOTHER'
'for' is the link.
(Other definitions for another that I've seen before include "encore?" , "Player or person not yet named or selected" , "second" , "Somebody else" , "Additional, one more" .)