vt.

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

   囚犯們在監獄牆下挖地道逃跑了。

2. （海，風等）侵蝕……的基礎
   The waves had undermined the cliff.

   波浪沖刷侵蝕懸崖的底部。

3. 暗中破壞；逐漸損害
   They are trying to undermine my position.

   他們在試圖損傷我的地位。

   The bad cold had undermined her health.

   重感冒損傷了她的健康。

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.