$ sudo apt-get update
$ sudo apt-get install dict-moby-thesaurus 

dict-moby-thesaurus is installed in your system.

Make ensure the dict-moby-thesaurus package were installed using the commands given below,

$ sudo dpkg-query -l | grep dict-moby-thesaurus *

You will get with dict-moby-thesaurus package name, version, architecture and description in a table

dict-moby-thesaurus package basic information: