$ sudo apt-get remove jackd2 

Uninstall jackd2 including dependent package

If you would like to remove jackd2 and it's dependent packages which are no longer needed from Ubuntu,

$ sudo apt-get remove --auto-remove jackd2 

Use Purging jackd2

If you use with purge options to jackd2 package all the configuration and dependent packages will be removed.

$ sudo apt-get purge jackd2 

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 jackd2 

See Also,