Would you say ideas with their genesis in a Permaculture meet-up, an earth-bag workshop or 10 years of exploration and immersion in the alternate space fit into what are generally thought of when we conjure the word start-up? Probably not. Here's what I'm riffing:
A start-down is an initiative based on facilitating existing resources (creation by facilitation), applying biomimicry to grow organisations from that base and adding a layer of technology & commerce to bridge disparate spheres of human existence.
Or some other fluff like that.