What Victor may take, left in misery (10)
I believe the answer is:
spoilsport
'misery' is the definition.
(I've seen this before)
'what victor may take left' is the wordplay.
'what victor may take' becomes 'spoils' (to the victor go the spoils).
'left' becomes 'port' (left side of a ship - opposite of starboard).
'spoils'+'port'='SPOILSPORT'
'in' acts as a link.
(Other definitions for spoilsport that I've seen before include "Damper" , "One who won't play?" , "misery" , "One who reduces others' pleasure" , "nark" .)