Cheating undermines confidence and independence: the cheater is a fraud, and knows that without dishonesty, he/she would have failed.
出自-2011年12月阅读原文
英语六级真题
You see it in faculty members who are pleased when their students make a discovery that undermines a cherished theory that they had put forward.
2017年6月六级真题（第一套）听力 Section C
柯林斯高阶英汉双解学习词典释义
VERB
（常指逐渐或反复）削弱，损害（情感、体制等）
If you undermine something such as a feeling or a system, you make it less strong or less secure than it was before, often by a gradual process or by repeated efforts.