日記|にっきnikki[0]heiban (flat)

1. noundiary; journal
   彼女かのじょはそのことを日記にっきに書かいた。↗

   She wrote about it in her diary.

• Synonym日誌にっしWrittenWritten-style word for work or official logs such as 「学級日誌」 and 「業務日誌」; leans toward factual records rather than personal reflections.
• Synonym日録にちろくWrittenWritten-style word for a book of day-by-day records; seen mostly in book titles and rare in everyday use.
• SynonymジャーナルFormalFormal loanword for periodicals or academic journals, as in 「医学ジャーナル」; for an ordinary personal diary, 「日記」 is the usual word.
• SynonymダイアリーNeutralLoanword for the diary book itself or a planner; common in product names. For actually keeping a diary in everyday speech, 「日記」 is the word to use.
• RelatedログNeutralLoanword for system or navigation logs, as in 「アクセスログ」; it does not refer to a personal diary.

For a personal diary, 「日記」 is the default. Use 「日誌」 for work or official logs, 「ログ」 for system records, 「ダイアリー」 for diary products, and 「ジャーナル」 for academic journals.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. 日々ひびの出来事できごとや感想かんそうなどを一いち日にちごとに記録きろくしたもの。