Well now a tough one! "69cuan" isn't a common term in any general dialect I have come across.
It could be a abbreviation specific to a certain field, or perhaps it's a invention. Maybe provide some background about where you saw this term, I could try to help. That might be It's possible turn into a mix of both. Should you decide to venture out the fresh air, remember to some sunscreen. Slang Term Every online community, no matter