When you are reading a complex article or a dense PDF on your Mac and encounter a word you do not recognize, your first instinct is likely to open a new Safari tab and Google the definition. This breaks your focus and relies on an active internet connection. To streamline your workflow, Apple includes a powerful, system-wide Dictionary app built directly into macOS. This app allows you to instantly define words, check synonyms, and even translate languages offline, right from the text you are currently reading.
How to Access the Dictionary Instantly
The true power of the macOS Dictionary is that it is deeply integrated into the operating system. You do not need to manually open the app from your Applications folder to use it.
- While reading an email, a webpage in Safari, or a document in Pages, locate a word you want to define.
- Move your mouse cursor directly over the word.
- Force Touch (Trackpad): If you are using a modern MacBook trackpad, press down firmly on the trackpad (a hard press, past the initial click).
- Keyboard Shortcut: Alternatively, you can hold down the Command (⌘) and Control (⌃) keys on your keyboard and tap the D key simultaneously.
A small, elegant yellow pop-up window will instantly appear directly over the word, displaying the full dictionary definition, pronunciation guide, and origin.
How to Configure Offline Dictionaries and Translations
By default, the Dictionary app relies on the New Oxford American Dictionary. However, if you are a student learning a new language or you prefer a British English dictionary, you can easily download additional reference books for offline use.
- Open your Applications folder (or use Spotlight search) and launch the Dictionary app.
- In the top menu bar, click on Dictionary and select Settings… (or Preferences).
- A window will appear containing a massive list of available reference sources, including Wikipedia, the Oxford Thesaurus, and dozens of bilingual translation dictionaries (e.g., French-English, Japanese-English).
- Check the box next to any dictionary you want to use.
macOS will immediately begin downloading that specific dictionary database to your hard drive in the background. Once the download is complete, you can use the Force Touch gesture to define or translate words even when you are completely offline on an airplane.
Prioritizing Your Results
If you selected multiple sources in the Settings menu (like a Dictionary, a Thesaurus, and a Translation guide), the pop-up window might become cluttered. You can control exactly which information appears first.
While still in the Dictionary > Settings menu, simply click and drag the different reference sources up or down the list to reorder them. If you place the Thesaurus at the very top of the list, your quick-look pop-up will always show synonyms before it shows the actual definition of the word.