How to get definitions of a word fast

If you are looking for a quick definition of a word or phrase, Google has a good way to get this.

Go to Google (Link)
In the search box, type "define:YOUR TERM"

For example,
define:xenophobia
define:united nations

You will get a quick list of lots of different defintions pulled from different sites across the Web. You can then quote these in your essays or reports, referencing the site that they come from.