I'm still waiting for the dictionary definition you promised with a link.

The reason you're so confused is because you think circular here actually means "in a circle".

It doesn't, it means distributed - & if you look through my profile you can see Bitcoin sent to me for goods & then Bitcoin I sent out for goods in return.

It wouldn't be a circular economy if I stopped the flow of distribution & sold for fiat on an exchange.

That's the only way it is not circular, hope this helps you out - if you're stuck here imagining a circle - well - you're absolutely highly regarded among your peers.