I was pretty certain that this tool existed. So, I confidently replied something along the lines of I'll look into it and get back to you. I fully expected to have an answer within the day if not within the week.
Well, it's been several months, and that's not because I forgot about this teachers question. It turns out that I could not easily find a tool to make online word sorts, especially one that didn't require a lot of technical knowledge. (If you know of one, please share this resource with me!) .
I was eventually able to find a great tool for building interactive learning activities called H5P (h5p.org). This resource allows you to create some great learning activities, but unfortunately, you have to have access to an LMS that supports it (Canvas, Blackboard or Moodle) or access to your own website (WordPress, Drupal) so that you can host it.
For those of you have access to these resources, I have a sample activity below as well as some links to information that I found on how to create it. You will need to adapt the information found in this links to your specific hosting environment, but you should get a general idea of the process that I followed to create the activity. Enjoy!