First, it's not just about distributing, it's about 4 freedoms: https://fsfe.org/freesoftware/basics/4freedoms.en.html
Second, non-technical people have no idea what "open source" means either, so you might as well be using the right term to educate them.
Third, you can capitalize Free Software to make it more obvious, or call it Libre/Free Software, or FOSS, etc... there are many options.
Open source is really bad because it does not imply any kind of freedom for the end user.
Generalistic and moderated instance.