deal-breaker
noun /ˈdiːl breɪkə(r)/
  /ˈdiːl breɪkər/
- something that causes somebody to reject a deal in politics or business砸买卖的事 - The candidate's support for the war is the deal-breaker (= people will not vote for the candidate because of it).候选人因为支持这场战争而失去了选民。 
- I would have bought the house, but the small backyard was the deal-breaker for me.我本想买下这所房子,但对我来说,小小的后院是个大麻烦。 
 
- The candidate's support for the war is the deal-breaker (= people will not vote for the candidate because of it).