$ sudo apt-get remove auth2db 

Uninstall auth2db including dependent package

If you would like to remove auth2db and it's dependent packages which are no longer needed from Ubuntu,

$ sudo apt-get remove --auto-remove auth2db 

Use Purging auth2db

If you use with purge options to auth2db package all the configuration and dependent packages will be removed.

$ sudo apt-get purge auth2db 

If you use purge options along with auto remove, will be removed everything regarding the package, It's really useful when you want to reinstall again.

$ sudo apt-get purge --auto-remove auth2db 

See Also,