vt.

1. 在……下挖坑道
   The convicts undermined the prison wall and escaped.

   囚犯们在监狱墙下挖地道逃跑了。

2. （海，风等）侵蚀……的基础
   The waves had undermined the cliff.

   波浪冲刷侵蚀悬崖的底部。

3. 暗中破坏；逐渐损害
   They are trying to undermine my position.

   他们在试图损伤我的地位。

   The bad cold had undermined her health.

   重感冒损伤了她的健康。

v.

1. erode the base or foundation of (a rock formation).
   ▸dig or excavate beneath (a building or fortification) so as to make it collapse.
2. make less powerful or effective, especially in a gradual or insidious way.