$ sudo apt-get remove libjs-mochikit 

Uninstall libjs-mochikit including dependent package

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

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

Use Purging libjs-mochikit

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

$ sudo apt-get purge libjs-mochikit 

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-mochikit 

See Also,