People distort words to the point of meaningless unless the use of those words are defended. "Open Source" is a term that is actively being defended.

The history of the term is very clear. The term was coined by Christine Peterson in a group session in 1998 with Todd Anderson, Larry Augustin, Jon Hall, Sam Ockman, Michael Tiemann, and Eric S. Raymond. Months later the OSI was created by the same people in order to manage that definition. There is nothing unclear here. "Open source" is defined by OSI and it has been defined by them from the very start.

If communities let others distort words, those words loose their meaning. As a well known example, the word "woke" which has long been abandoned by the community that coined it.

"Open source" is an actively defended term by the organisation that originally defined it and the community around them.