You only need to uninstall the zeitgeist (if it is installed) and the zeitgeist-core packages. The following command on your terminal should do it:
sudo apt purge zeitgeist zeitgeist-core
There’s another related package that you should not uninstall, called libzeitgeist-2.0-0. This is simply a library package that allows other applications to access zeitgeist functionality (which you have in the meantime removed). Nautilus depends on that library. So leave it.