Well, I suppose it depends on what you're talking about. If you're talking about Tor hidden services, "Tor hidden services" seems like a pretty good alternative.

Yes, non-technical people don't know what this means, but they can learn. Non-technical people don't know what the "dark web" means either, but it sure sounds mysterious, and has the added danger that they often erroneously think they do, but have no idea what they're talking about.