Jessica Schwartz, no relation to me, from Google posted a thread at Google Web Search Help with a link to a new video Google made on how to use Google to find definitions.
She said the video was made by her teammates, Matt and Chris. The video is a rap video on how and when to use Google to fine the definitions of words you might not understand.
Here is the video:
Google provides pronunciation, click to hear and more use cases of that word. It also gently links to competing dictionaries such as Dictionary.com, Answers.com, Merriam-Webster and The Free Dictionary.
Forum discussion at Google Web Search Help.