1. 为人所讨厌的人或物：bet your boots || 必然, 有把握 | bete noire || 为人所讨厌的人或物 | bete || 野兽 愚人
1. 讨厌鬼；眼中钉，肉中刺
If you refer to someone or something as your bete noire, you mean that you have a particular dislike for them or that they annoy you a great deal.
e.g. Our real bete noire is the car boot sale.
我们最烦那些用汽车后备箱摆摊卖旧货的。