$ sudo apt-get remove gkrellm-tz 

Uninstall gkrellm-tz including dependent package

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

$ sudo apt-get remove --auto-remove gkrellm-tz 

Use Purging gkrellm-tz

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

$ sudo apt-get purge gkrellm-tz 

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 gkrellm-tz 

See Also,