A very handy keyboard shortcut that I like to use a lot is Dictionary Lookup, command+control+d. By placing the cursor over a word and using the shortcut this is a great way to find the meaning quickly. The word is highlighted in yellow and a small popup window shows a dictionary, thesaurus and even Wikipedia entries pertaining to it!
However recently I found an even easier way using the trackpad! As before, place the cursor over the word that you want to lookup but now simply use three fingers to tap the trackpad.
Now isn’t that just super-mundanely thaumaturgical ?