I was a fan of the package
Dictionaries but is seems that it is no available and that will not be re-included. The package’s page in package control is here, indicating that the package was removed.
Anyway, the package is in GitHub and it can be installed from the repository. The steps follows:
mv Dictionaries-master Dictionaries
mv Dictionaries ~/.config/sublime-text-3/Packages
The steps described here are also in the package’s repository (at the end).