The constraint made me realize that the complex word isn't that helpful when the other person doesn't know much behind the word. You need to get inventive, and at some point, you might start having fun. I used this to explain encryption, and from the feedback I've got, I seem to have done a good job. It gets repetitive at times, but I managed to slip in PKI, password storage, and a brief summary of the Crypto Wars.
https://theandrewbailey.com/article/177/Hidden-Writing