Nonsense.
On the one hand, you have the economics profession as it’s currently practiced. They define inflation as a change in the general price level. That includes every popular textbook, every reputable economist, every relevant government agency, every major business newspaper – and not just in English, but worldwide. The entire field, across the entire globe, has settled on a single adequate definition as a change in the general price level. That is how the experts actually define it.
On the other hand, you have a handful of commenters on the internet who prefer the definition that’s 70 years out-of-date.
There is no dispute here. The correct definition is the one professionals actually use around the world.