$ sudo apt-get remove gniall 

Uninstall gniall including dependent package

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

$ sudo apt-get remove --auto-remove gniall 

Use Purging gniall

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

$ sudo apt-get purge gniall 

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 gniall 

See Also,