Victor, ace in battle, needs break (8)
I believe the answer is:
vacation
'break' is the definition.
(I've seen this before)
'victor ace in battle' is the wordplay.
'victor' becomes 'V' (phonetic alphabet: alpha, bravo, charlie etc.).
'ace' becomes 'a' (abbreviation).
'in' indicates putting letters inside.
'battle' becomes 'action' (military action).
'a' going into 'action' is 'acation'.
'v'+'acation'='VACATION'
'needs' is the link.
(Other definitions for vacation that I've seen before include "break" , "Leave" , "An American holiday" , "Leisure time away from work" , "Holiday period" .)