$ sudo apt-get remove open-cobol 

Uninstall open-cobol including dependent package

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

$ sudo apt-get remove --auto-remove open-cobol 

Use Purging open-cobol

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

$ sudo apt-get purge open-cobol 

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 open-cobol 

See Also,