There's a difference between a word gaining a second meaning, and one meaning effectively replacing the other completely.
icebraining mentioned "gay". Today, who in their right mind would call a joyful person gay? That's what the term originally meant, but has since has been completely replaced with meaning "homosexual".
The term "Open Source" is the same. It may have meant something different some one and a half decades back. That meaning, however, has completely fallen out of use. Just as "gay" meaning "joyful" has. It's deceptive to use it that way.
"That meaning, however, has completely fallen out of use."
I'm not convinced of that - in fact, I think that is a little naive.
I don't believe that the OSI definition is completely accepted by the uneducated population at large, and don't believe that the term "open source" is not used by various software companies in ways that mislead and obfuscate the OSI meaning.
I'll quote Mr Stallman:
"However, the obvious meaning for the expression “open source software”—and the one most people seem to think it means—is “You can look at the source code.” That criterion is much weaker than the free software definition, much weaker also than the official definition of open source. It includes many programs that are neither free nor open source."
"The term “open source” has been further stretched by its application to other activities, such as government, education, and science, where there is no such thing as source code, and where criteria for software licensing are simply not pertinent. The only thing these activities have in common is that they somehow invite people to participate. They stretch the term so far that it only means “participatory”."
I don't accept that the other meanings have completely fallen out of use.
icebraining mentioned "gay". Today, who in their right mind would call a joyful person gay? That's what the term originally meant, but has since has been completely replaced with meaning "homosexual".
The term "Open Source" is the same. It may have meant something different some one and a half decades back. That meaning, however, has completely fallen out of use. Just as "gay" meaning "joyful" has. It's deceptive to use it that way.