If you mean the opposite of a personal journal:
* Public record: This refers to official documents, like historical records, government documents, etc., which are open to the public.
* Social media: This involves sharing thoughts and experiences with a wider audience, instead of keeping them private.
* Novel/Memoir: These are written accounts of experiences, but they are intended for publication and consumption by others.
If you mean the opposite of the word "diary" as a specific object:
* Notebook: A general term for a book with blank pages for writing.
* Journal: While often used interchangeably with "diary," it can also refer to academic journals or specific types of journals (e.g., travel journal).
* Logbook: A record of events, observations, or data, typically used for specific purposes like ship logs or flight logs.
Ultimately, the "opposite" of a diary depends on the context and what you are looking for. It's important to clarify what you mean before finding a true opposite.