Losing king, kept ace in original card game (8)
I believe the answer is:
patience
'card game' is the definition.
(I know that patience is a type of card game)
'losing king kept ace in original' is the wordplay.
'losing' is a deletion indicator.
'king' becomes 'K' (abbreviation for king in chess).
'original' indicates an anagram.
'kept'+'ace'+'in'='keptacein'
'keptacein' with 'k' taken out is 'eptacein'.
'eptacein' is an anagram of 'PATIENCE'.
(Other definitions for patience that I've seen before include "Waiting calmly" , "Calm endurance as in card game for one" , "Gilbertian dairymaid" , "Musical work" , "Waiting without complaint" .)