Aged men prepared for final stage (7)
I believe the answer is:
endgame
'final stage' is the definition.
(final stage of a chess game)
'aged men prepared' is the wordplay.
'prepared' indicates anagramming the letters.
'aged'+'men'='agedmen'
'agedmen' with letters rearranged gives 'ENDGAME'.
'for' acts as a link.
(Other definitions for endgame that I've seen before include "moves before mating" , "close to board meeting" , "contest's final stage" , "Denouement (chess)" , "closing moves on chessboard" .)