[This article was originally published on May 3, 2005 and has been brought to the top of the list by recent requests from numerous MacDailyNews readers.]

Users of Apple’s new Mac OSX 10.4 Tiger operating system may have already figured out that if they highlight any word displayed as text in Apple’s Safari 2.0 (and other Tiger apps that handle text like TextEdit, for example) and Control-Click (right click for multi-button mouse users) the highlighted word, they can choose “Look Up in Dictionary” from the resulting Contextual Menu. Tiger Safari users, try it now on any word on this page.

That’s a pretty nice feature, but did you know that if you simply place your cursor over any word and press Command-Control-D, the Dictionary definition will just pop right up? Click “More” to launch the Dictionary (and Thesaurus) application itself and use the “Oxford Dictionary / Oxford Thesaurus” drop down menu to switch between the two.

Now for the ultimate: Hold down Command-Control-D as you move your cursor over multiple words and watch what happens! (Bonus secret: you can let go of the D key and as long as you continue holding Command-Control, it’ll keep working.) Even better yet, open the Keyboard & Mouse system prefs’ Keyboard Shortcuts. Assign an unused function key like F7 to “Look Up in Dictionary.” Now, just hit F7 to toggle the Dictionary feature “on” and and start mousing around the page. Hit F7 again to turn it off.

The system-wide Dictionary works in Safari’s text input boxes, too. So, no more misused, misspelled words for Tiger Safari users in your Reader Feedback comments, okay?

[UPDATE: May 3, 2005, 2:03pm ET: Thanks to MDN reader "Fork Ball" for alerting us to a QuickTime 7 (H.264) movie of the feature in action that's posted over at macosxhints.com. Users with QuickTime 7 who might not yet have Tiger can see how the feature works here.]