Open source simply means the source is publicly available. There can be, and often are, restrictions on how the source can be used.

It doesn't simply mean that. It means some fairly specific things [0], one of which is that there can be no "discrimination against fields of endeavor", which restriction on commercial use is.

[0] - https://opensource.org/osd-annotated

I think you've got visible source in mind.

"Source available" is the preferred term of a particular commercial GrapheneOS.org "competitor".