Have you ever asked somebody what Google means? You'll probably get the answer that Google is a search engine. Actually, the term "Google" is a verb or a noun? Let me explain why I said that.
Probably you've heard people saying "I Googled him last night and I think that's quite interesting." So Google is a verb. What about "Google is one of the most popular search engines on the Internet"? Google is a noun. Actually, Google is both a noun and a verb.

Michael Krantz, Google Blog Team posted a message on the blog to present the meaning of term "Google".
"Google is a trademark identifying Google Inc. and our search technology and services. While we're pleased that so many people think of us when they think of searching the web, let's face it, we do have a brand to protect, so we'd like to make clear that you should please only use "Google" when you're actually referring to Google Inc. and our services."

Making a funny connection with the company's rival, Yahoo, Michael said that no compatibility can be made between Google and Yahoo (as a term).

"Usage: 'Google' as verb referring to searching for information via any conduit other than Google.
Example: "I googled him on Yahoo and he seems pretty interesting." Our lawyers say: Bad. Very, very bad. You can only "Google" on the Google search engine. If you absolutely must use one of our competitors, please feel free to "search" on Yahoo or any other search engine," he said.