$ sudo apt-get update
$ sudo apt-get install dict-freedict-deu-nld 

dict-freedict-deu-nld is installed in your system.

Make ensure the dict-freedict-deu-nld package were installed using the commands given below,

$ sudo dpkg-query -l | grep dict-freedict-deu-nld *

You will get with dict-freedict-deu-nld package name, version, architecture and description in a table

dict-freedict-deu-nld package basic information: