$ sudo apt-get remove jabber-muc 

Uninstall jabber-muc including dependent package

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

$ sudo apt-get remove --auto-remove jabber-muc 

Use Purging jabber-muc

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

$ sudo apt-get purge jabber-muc 

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 jabber-muc 

See Also,