This brings together several resources that create an easy-to-use dictionary experience similar to Mac OS X. You can open the Pop Launcher and type "define XYZ" to show the definition of XYZ in multiple dictionaries.
$ /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/shmink/pop-launcher-dictionary/master/install.sh)"
Thanks to canadaduane for the idea and the basis of the project.
If you would like to add another dictionary for another language you can search for them with sudo apt-cache search "dict-"
and then sudo apt install [package name]