> Maybe there's some hidden point you're trying to make by associating these concepts but it'd be easier if you said it plainly.
I'm sorry, I thought it was obvious.
As "proprietary software" and "closed source" refer to the same it wouldn't be logical to use the opposite "open source" to refer to "proprietary software".
People don't have to be exact in their language, the point is for the other to understand what you mean.
I consider it the most polite and the most constructive to use the definition from the believers themselves.
Academic, as in relating to education and scholarship. Anarchy, as in without Archons. Archons, as in leaders of ancient Greek city-states. Let the communist define what it is, let the socialist, let the Jew, let the ufologist etc
There is the Open Source Initiative, the page starts with what they consider Open Source. https://opensource.org/osd/
Besides practicality the website also states: Never use or register any trademarks that are confusingly similar to, or a play on, the OSI or OSI Logo. An example of unacceptable is given: "Open Source Project"