It seems there are some rather large differences in what I get when Bing and Google do their instant search term suggestions for something as vague as “what is”:

These results may also imply something about how much data has been gathered and is used for my personalized versions of both searches too. However, I don’t remember searching for any of these as either a "what is" search or for any of the other search terms.

Parliament? Gout? Gluten? The Illuminati? Strange indeed, but perhaps the makings of a great mystery-thriller novel!