Clear signal to go after victory (9)
I believe the answer is:
vindicate
'clear' is the definition.
(I've seen this before)
'signal to go after victory' is the wordplay.
'signal' becomes 'indicate' (synonyms).
'to go after' is a charade indicator (letters next to each other).
'victory' becomes 'v'.
'indicate' after 'v' is 'VINDICATE'.
(Other definitions for vindicate that I've seen before include "support" , "Justify or exonerate" , "Avenge or exonerate" , "Successfully defend" , "Clear of blame" .)