/ 5daIErI; `daIErI/ n (book used for a) daily record of events, thoughts, appointments, etc 日记; 日志; 日记簿: keep (ie write regularly in) a diary 记日记.
> diarist / 5daIErIst; `daIErIst/ n person who writes a diary, esp one that is later published 写日记的人, 日记作者（尤指内容供日後发表者）.