I learned a little about this word this semester in Hebrew 201. I don't
know enough to tell you when exactly the word crept into the Hebrew
language, but I do know that 'bizbuz', like other four-letter verb roots,
is of foreign origin. If I am not mistaken, the original language is
Arabic.
BTW, all word roots of this type are distinct in that they are composed of
a 2 letter series repeated once. (Bet-Zayin, Bet-Zayin in the case of
'bizbuz'.)
Florence, you can try emailing my professor at <litov@umbc.edu> for more
details. And you can tell him how much I enjoyed his class.
Linguistically yours,
Daniel Pearson