1. undermine a wall (¼ºº® ¹Ø¿¡ ¶¥±¼À» ÆÄ´Ù) 2. It undermined her confidence in us. (±×°ÍÀº ¿ì¸®¿¡ ´ëÇÑ ±×³àÀÇ ½Å·Ú¸¦ ÈѼÕÇß´Ù) 3. The sea had undermined the cliff. (¹Ù´å¹°ÀÌ Àýº® ¾Æ·¡¸¦ ħ½ÄÇÏ°í ÀÖ¾ú´Ù) 4. My father's health was undermined by drink. (¾Æ¹öÁöÀÇ °Ç°Àº ¼ú·Î ¼Õ»óµÇ¾ú´Ù)