The internet is a series of connected networks. That's the "inter-" part. This is one network. In other words, an intranet.
If you want to call a single standalone network the same thing as the global set of interconnected networks, that's up to you.
I think if you gave people what I'm building and told them they're on the internet, they'd strongly disagree with your idea of the word "internet" means. 😂
