Call it, future newbie].
Buncaik pretty much means a newbie to become, in the future. The term buncaik started on a quite large fourm, the roblox.com fourms. Roblox.com's fourms is composed mainly of kids of the age 4-13, so it is likely that this orginated as it is less mean than common internet slang.
One interesting thing though, is that a moderator on the fourm hated the word and began banning people for use of it. This was resloved the following day after a fair amount of uses complained and read the ToS finding the moderator had broken the ToS herself.
Back on subject, once it has reached the next year, the term buncaik is dismissed and newbie is used.
09 Player: The 10er buncaiks are coming!
09 Moderator: BAN FOR 7 DAYS
09 Player: Ello Newbie!
10 Player: I'm new :D