Tomeplover: Dictionary & Thesaurus

A dictionary extension that lets you look up a word without leaving the page: double-click it, and a small card shows the definition, examples, synonyms and pronunciation.

The whole dictionary lives inside the extension. There is no online service behind it that can stop answering, no account, and nothing you read or look up leaves your browser. It keeps working with the network switched off.

What is in the card

• Definitions grouped by part of speech, with an example where the dictionary has one
• A thesaurus: synonyms sorted by meaning, and antonyms where they exist
• Pronunciation: IPA transcription where available, and a Say button that uses a voice installed on your system
• Word forms: double-click “mice”, “running” or “better” and you get “mouse”, “run” and “good”
• Close spellings when a word is not found, so a typo is not a dead end
• Click any synonym to open its article, and go back with one click

Your choice of access
You do not have to allow access to all sites. Select a word and use the right-click menu or the keyboard shortcut, and the card appears on that page only. Double-click on every page is an option you can turn on or remove at any time.

It stays out of your way

• No card while you type in forms, search boxes and editors
• Pick the trigger: double-click, double-click with a key held, selected text, or only the menu and shortcut
• Turn it off for a site in one click
• The card always stays on screen, follows your light or dark theme, and closes with Esc

A history that belongs to you
Every word you look up is saved in this browser with its date. Search it, sort it A to Z, remove a word or clear the list, undo a mistake, and export it to CSV or JSON. You can turn the history off, and words from private windows are not saved.

What to expect
The dictionary is English only, built from Open English WordNet with about 128,000 words and phrases. The interface is available in 16 languages, but the articles are in English. Not every word has a transcription, the sound depends on the voices on your system, and slang, very new words and small grammar words such as “the” and “of” are often missing.

Works offline. Your data stays in your browser. This version is free.

Permissions: storage keeps your settings and history in this browser; activeTab and scripting show the card on the page where you ask for it; contextMenus adds the right-click item. Access to all sites is optional and is used only to notice a double-click.