Vote in favor (3)
I believe the answer is:
yea
'vote in favor' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for yea that I've seen before include "'She loves you, ... ... ...' (The Beatles)" , "-- or nay?" , "Certainly (archaic)" , "Archaic affirmative answer" , "Emphatic agreement" .)