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