Key Combination to Bring Up An Instant Dictionary

This is an often forgotten Mac tip in Mac OS X. To bring up an instant definition of a word your mouse arrow may be pointing to, leave your mouse cursor pointing to the word you want defined and while the cursor is on your word, hold down the control and command key (apple key) and while those two keys are held down tap the D key. A dictionary definition of the word your cursor is pointing at will be visible.