FOS: Stands for "Free Operating System" as an inclusive term. Includes GNU/Linux, NonGNU/Linux, *BSD that are meant to liberate ones computing.
I'll start, I use Linux Mint on my laptop that I use for work daily. It uses the latest Xanmod linux kernel and flatpaks for apps with GNU Guix providing everything else.
Good semantics argument. Honestly I was testing out this whole new FOS acronym to be more generic and a solution to "FOSS" while still having the benefit of being an easy acronym.