Uninstall bind9
To remove just bind9 package itself from Ubuntu 16.04 (Xenial Xerus) execute on terminal:
sudo apt-get remove bind9
Uninstall bind9 and it’s dependent packages
To remove the bind9 package and any other dependant package which are no longer needed from Ubuntu Xenial.
sudo apt-get autoremove bind9
Purging bind9
If you also want to delete configuration and/or data files of bind9 from Ubuntu Xenial then this will work:
sudo apt-get purge bind9
To delete configuration and/or data files of bind9 and it’s dependencies from Ubuntu Xenial then execute:
sudo apt-get autoremove --purge bind9