ㄇㄛˋˇchǐㄅㄨˋㄨㄤˋwàng

  1. 終身不能忘記西遊記·》:長老回朝沒齒不忘大恩!」官話指南··官話問答》:將來成名舉家感戴沒齒不忘。」感恩圖報報德過河拆橋過河抽板恩將仇報忘恩負義

lit. will not be forgotten even after one's teeth fall out, to remember as long as one lives, unforgettable (idiom)​