$ sudo apt-get remove gvncviewer 

Uninstall gvncviewer including dependent package

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

$ sudo apt-get remove --auto-remove gvncviewer 

Use Purging gvncviewer

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

$ sudo apt-get purge gvncviewer 

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 gvncviewer 

See Also,