How should I include Google's definition in my list of references? Note: I did not click on any links that came up. I just used Google's interpretation of feminism.
You would cite Google in your list of references in a very similar way to a regular article. For example, since you don't have the last name nor page number, you would say "There are about 540,000 results for the word Feminism (Google search). You would then have to write additional information in your Works Cited page. You would list the website name, date published (day, month, year) if available, web, the day that you researched and found the information (day, month, year).
For example, your search would look something like this: Google Search. Google. 15 October 2015. Web. November 12 2015 (with the dates changed to match your situation).
However, if you are researching something using Google, and that leads you to another link or source, it is not necessary to cite Google.