Having been interested in business since before the dot-com book, I've seen "Startup" transform from "New business, dealing with new business problems" to the very SV-driven notion that it's a new business expressly designed to scale quickly.

Words might need to mean something, but there's already been a lot of drift here.

The meaning of words has always been a negotiation.

That's of course not just happening now, it has always been a problem with the term. There has never been wide industry agreement as to what it means, going back decades.

That's how you end up with the media referring to 10 year old type companies that have thousands of employees as start-ups. I don't think a definition for it is going to get narrowed now, it will probably always be a broad/loose term.