Official? In what sense?

In the sense of being the widely accepted authority on the matter.

That’s another assumption. It might be widely accepted within your circle, but most people using the word I would bet don’t even know it exists. So for them it isn’t an authority. A dictionary might be.

I certainly do not recognise any charity’s right to define a word, so it is not official to me - or, apparently, to the OED or Wikipedia, and I would bet most other dictionaries and people.

I certainly don't care about your opinion, so I don't give a shit what you recognize as authority.

Most people in the open source community recognize OSI definition as authoritative. "Muh assumption" - if you want data, look at the comment section in this article, most people disagree with you. You may have your microcosms of people who don't know/don't care about history of open source/free software, but your ignorance doesn't grant you any authority over language, either.

Use the language any way you want, but stop throwing tantrums when people rightfully tell you that you're using it wrong.