Definio - Multi-Source Definitions

The English dictionary that lives in your sidebar. Look up 450,000+ words from three sources at once — without leaving your page. No sign-in, no ads, no popups.

🔍 THREE WAYS TO LOOK UP WORDS
Select any text on a webpage — the definition loads automatically. Right-click and choose "Look up in Definio." Or press Alt+Shift+D to open the sidebar from anywhere.

📖 TABBED SOURCES
Switch between Definio's 450K+ word database, Oxford Dictionary, and Wikipedia with a single tap. Your last-used source is remembered. If a source has no result, it falls back automatically.

🔊 PRONUNCIATION
Hear any word spoken aloud with built-in text-to-speech. Phonetic transcriptions shown alongside every definition.

🕘 SEARCH HISTORY
Recently searched words are saved locally. Browse, re-search, or remove individual entries. Toggle on or off in settings.

⚙️ FULLY CONFIGURABLE
Show or hide definitions, examples, pronunciation, synonyms, and antonyms. Adjust font size. Switch between light and dark themes.

⚡ FAST & PRIVATE
Lightweight, no tracking, no ads, no account required. Open the sidebar and start looking up words immediately.

⌨️ KEYBOARD SHORTCUT
Alt+Shift+D (Windows/Linux) or Option+Shift+D (Mac). Customizable via chrome://extensions/shortcuts.

Originally built as a better alternative to Google Definitions — because the default dictionary lacked the depth and flexibility people wanted.

⚠️ KNOWN LIMITATIONS
- Does not work with PDF files viewed in the browser
- Open the sidebar first, then select text — or use the right-click menu