diary

diary — noun

1. a book or digital file where you regularly write about your private thoughts, fe

1.nounB1
Definition

a book or digital file where you regularly write about your private thoughts, feelings, and the things that happen in your life

Example

Rachid writes in his diary every night before going to sleep.

collocation: write in + possessive + diary

Linh kept a diary throughout her trip to Japan.

collocation: keep a diary

Common collocations
  • keep a diary
  • diary entry
  • write in a diary
  • personal diary
  • secret diary
  • video diary
Synonyms
  • journal

    slightly more formal; often used for a reflective or professional record rather than everyday private thoughts

  • log

    more factual; records events in sequence without personal reflection

Grammar Patterns

keep + a + diary

write in + (possessive) + diary

diary + entry

Usage Note

Diary in this sense focuses on recording past experiences and private emotions. It is common among teenagers and adults who use writing as a way to reflect on their daily lives.

Common Mistakes

I wrote down my meeting times in my diary.' (when meaning a planner)
I marked my meeting times in my appointment diary.
Use 'diary' for personal/emotional entries; use 'appointment diary' or 'planner' for scheduling future events.

2. a book or calendar that gives each day its own place, where you note down upcomi

2.nounB1
Definition

a book or calendar that gives each day its own place, where you note down upcoming appointments, meetings, and tasks that you must remember

Example

The doctor checked her diary to find a free time for the patient.

collocation: check + possessive + diary

Renata marked the meeting date in her diary so she would not forget.

collocation: mark + in + possessive + diary

Common collocations
  • work diary
  • appointment diary
  • desk diary
  • check one's diary
  • mark in one's diary
Synonyms
  • planner

    more common in American English; often implies a structured book with calendars and to-do lists

  • appointment book

    neutral term focused on scheduled meetings; used especially in professional settings

  • calendar

    can be digital or wall-based; broader than diary

Grammar Patterns

check + (possessive) + diary

mark + in + (possessive) + diary

diary + noun (diary date)

Usage Note

In British English, 'diary' is very commonly used for this sense — a book for scheduling future plans. In American English, 'planner' or 'appointment book' is more typical, though 'diary' is understood. Distinguish from sense 1 by topic: future events vs. past personal reflections.

Common Mistakes

I read her diary to see what appointments she had.' (sounds like reading private thoughts)
I checked her diary to see what appointments she had.
Use 'check' instead of 'read' when looking at scheduled future events.

Word family

  • diarist
    nounC1
  • diaristic
    adjectiveC2

Synonym discussion

Sense: noun/1

A 'diary' typically contains personal, everyday thoughts and feelings, written for oneself. A 'journal' is similar but often implies more thoughtful, reflective writing — it may be used in a professional or academic context (e.g., a research journal). A 'log' is a factual, chronological record of events, such as a ship's log or a maintenance log, with no personal emotion. A 'blog' (short for weblog) is an online diary or journal that is usually public and may have multiple readers. For example, you might write in your diary before bed (private), keep a travel journal (reflective), record daily tasks in a work log (factual), or publish a food blog (public and shared with an audience).

diary ↗journal ↗log ↗blog ↗

Common collocations

Nouns

Adverbs

Phrases

  • diary entry
  • diary writing
  • diary format

Prepositions

Etymology

Latin

The word 'diary' comes from Latin 'diarium', meaning 'daily allowance', which itself comes from 'dies' (day). In ancient Rome, a diarium was the daily portion of food or money given to a worker. Over time, the word shifted to mean a daily record of events, and by the 16th century it was used in English for a book in which one writes about each day.