沒ㄇㄛˋ齒ㄔˇ難ㄋㄢˊ忘ㄨㄤˋmòchǐ‑nánwàng

简没齿难忘

  1. 終身難以忘記。例 「您的提攜之恩，我沒齒難忘」。

英hard to forget even after one's teeth fall out (idiom)​; to remember a benefactor as long as one lives, undying gratitude