Click Define by HalfToast

Click Define turns every word on the web into a quick lookup. Just double-click, no shortcuts, no menus, no leaving the page. On Firefox for Android, long-press instead.

• Double-click any word (or long-press on mobile) to open a small popup with its definition.
• Hundreds of languages via Wiktionary. When a word has entries in multiple languages, a dropdown lets you pick which one to view. Defaults to the page's language automatically; settable in preferences.
• Pronunciation with IPA and an audio button in any language Wiktionary covers. It follows the language shown in the popup, so "Katze" gives the German pronunciation and "chien" the French one.
• Synonyms and antonyms as clickable chips - click one to look it up; a back button returns to the previous word.
• Inflected-form awareness - for entries that just point elsewhere ("plural of box", "simple past of run", "misspelling of receive"), a chip in the header jumps you to the base word. Optional setting to make this automatic.
• Lemma fallback so inflected forms without their own entry still resolve (e.g. "happily" → "happy").
• Sticky popup that scrolls with the word being defined.
• Fast and resilient - the definition appears as soon as it's ready and the extras fill in after. A slow dictionary service can't hang the popup, transient errors retry silently, and a clear retry button shows when something really fails.
• Light and dark mode that follow your system theme, or pick one in settings.
• Privacy-first - only the word you double-click is sent to public dictionary APIs. Page content, browsing history, and personal data are never collected or transmitted.

When you double-click a word, Click Define queries Wiktionary for definitions and pronunciation in any language, the Free Dictionary API as an English fallback, and Datamuse for synonyms/antonyms. No accounts, no API keys, no tracking.

Press Esc or click outside the popup to dismiss it.