$ sudo apt-get remove grass642

Uninstall grass642 including dependent package

If you would like to remove grass642 and it's dependent packages which are no longer needed from Ubuntu,

$ sudo apt-get remove --auto-remove grass642

Use Purging grass642

If you use with purge options to grass642 package all the configuration and dependent packages will be removed.

$ sudo apt-get purge grass642

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 grass642

See Also,