When you include "define," "what is," or "what are" in your query in front of a word, phrase, or acronym, Google displays one Glossary definition above your search results. Google Glossary provides definitions for words, phrases, and acronyms that Google finds on web pages. The Glossary is good for finding definitions for terms that aren't in some dictionaries, e.g., slang words, technical terms, ethnic words and other specialized terms.

In February of 2003, Google acquired Pyra Labs, a company that makes it easy for you to create your own blog. What's a blog? Let's ask Google to define the term.

You can search for blogs with Google, in the same way that you search for other documents. You can easily create a weblog (blog) post pointing to the web page you're visiting by pressing the "BlogThis!" button on the Google Toolbar and publish your thoughts on the web so others may find them. You can learn more about this feature on toolbar.google.com/button_help.html.

Google Glossary can also find definitions of acronyms.

When your query includes the "define:" operator, Google displays all the definitions it finds on the web.