open source means the source is.. open. It does not mean the source is necessary free. These two points are not in conflict.

That is not how we define open source. See:

https://opensource.org/osd

Openness is much more than “source available”. Open for use by others is an important part of that.

"unlicensed open source" exists, however -- it is a real thing, referred to as open source, despite that it cannot be used legally.

i.e. https://www.synopsys.com/blogs/software-security/unlicensed-...

Yes