つめのあか

つめのあか 【爪の垢 】▸ 彼にはつめのあかほども ｟少しも ｠誠意がない He does n't have an atom of sincerity .つめのあかをせんじて飲む ▸ 彼のつめのあかでもせんじて飲んで ｟教訓を得て ｠，もっと分別をわきまえなさい You should take a lesson from him [(見習う ) learn from his example ] and know better .