"Jubjub" was derived from the English expression "Lovely jubbly". "Jubbly" used alone does not mean the same as 'lovely jubbly'. Generally, jubbly is used to describe someone who has done
something stupid, silly, clumsy or immature.
ex. "Gow, you're such a jubbly! I can't believe you've locked us
out of the car again!"
ex. "We are definitely lost! Why haven't you stopped for directions? Gaa! When did you turn into such a jubbly?"
However, "jubjub" is a shortened, more
affectionate derivative of "jubbly". It is used in an endearing fashion, usually with a loved one or child.