Who made opensource.org the king?
If you want a different definition, all you have to do is invent a new term. The term "open source" was invented by the people who made the definition at the URL above. (It had existing uses, but the people who made the definition above were the first to apply the term to software or software licenses.)
As for being the first to apply the term to software licenses, yes you're correct there. But that's the inherent source of this endless confusion: they took an existing term which didn't relate to licenses, and redefined it to be entirely about licenses.
It's quite ironic to say "If you want a different definition, all you have to do is invent a new term" since that's literally what the OSI failed to do!
Edit to add: I would appreciate it if downvoters would cite what specific part of the linked article you disagree with, considering that it has numerous instances of irrefutable proof of "open source" being used to describe software prior to 1998, including by famous folks like Bill Joy.
A bunch of for-profit companies proped OSI up to exclude "open source" projects that are not free to use for businesses so they can profit more from OSS community and you eat it up.
As does the Debian Free Software Guidelines.
(Also, I think you mean trademark case, not copyright case.)