Board Thread:Support Requests - Community Management/@comment-27004217-20150921192339/@comment-4018164-20150921220311

Follow these steps: If indexing by search engines isn't an option for you, the best solution is: don't put it anywhere in the internet to begin with. Besides, although you could make parts of a website "unindexable" (if that's a real term), as a business, Wikia's occupation is to achieve higher search results.
 * 1) Go to Special:CreateNewWiki
 * 2) Enter a subdomain for your wiki.
 * 3) Pick a name for your wiki.
 * 4) Close the Create New Wiki tab in your browser.
 * 5) Find a pencil and a piece of paper and start writing.

So, if you're not dealing with topsecretgovernmentarea51illuminati21-like stuff, you can still set up your own wiki and make it only visible to users that are given a specific user group.