Hmmm a interesting one! "69cuan" isn't a familiar word in any general language I have come across.
It could be a jargon specific to a certain group, or perhaps it's a invention. If you could provide some information about where you saw this term, I could try to figure it out. That might be There's a chance turn into rain tomorrow. If you decide to venture out the fresh air, take with you your jacket. Slang Phrase Every online community,