It’s just an application in the Applications folder, but there are lots of quick ways to get at the deep information stored in the Mac’s Dictionary.

There are two ways to view Dictionary: as a pop-up panel, an unobtrusive semi-transparent window with basic information; or as a normal application with a full-fledged window. Use it either way.

There are two ways to access Dictionary: through a contextual menu, which is what you get when you right-click on items; and through Dictionary’s main window, like any other application.

Try right-clicking on a word in a web page or a text document. You’ll see Look Up in Dictionary in the contextual menu. Choose it, and whammo! You’ve got your definition. It’s that easy.

You can improve on that little definition, however. Open the Dictionary application, then go to its Preferences (in the application menu, to the right of the Apple menu:

• Check the boxes for all the sources you want information from when you look up a word. (I’ve got them all checked.*) Selecting individual sources in the list sometimes gives you more options: for Dictionary, for example, you can choose which pronunciation you want displayed.
• (10.6 and earlier) In Contextual Menu, below the list of sources, choose whether you want a panel or a full window to open when you right-click on a word.
• Choose a font size as well. There are buttons for enlarging and reducing text size in the main window so don’t think too hard about this setting now.

Close the Preferences window and you’re done!

Power Tips

• Ctrl-Command-D on any word in almost any Mac app, including browsers. (Yet another benefit of ditching Microsoft Office!)
• Lion Users: try a 3-finger tap on a word to get a definition. Sweet.
• When reading in Dictionary, you can click on words to get their definitions too. It’s a great way to delve further. Use the forward and back buttons like in Safari and Finder.

*If you have languages besides English enabled on your Mac you might have the option of a language dictionary too.