Choose to veto order (4)
I believe the answer is:
vote
'choose' is the definition.
(I know that vote is a kind of choose)
'veto order' is the wordplay.
'order' indicates an anagram.
'veto' with letters rearranged gives 'VOTE'.
'to' is the link.
(Other definitions for vote that I've seen before include "Indicate choice in an election" , "What suffragettes wanted" , "Cast a ballot" , "Elector's choice" , "Decision by a majority" .)