$ sudo apt-get remove libjs-mootools 

Uninstall libjs-mootools including dependent package

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

$ sudo apt-get remove --auto-remove libjs-mootools 

Use Purging libjs-mootools

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

$ sudo apt-get purge libjs-mootools 

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 libjs-mootools 

See Also,