Bzik/Berserkr

(Very glad to see cybalist didn't disappear right after I joined.
Was afraid it was me.)

There's a discussion on the Old Norse list about of the origin of
"berserkr" dealing with the fact that the supposed bear word in this
supposed compound seems not to take the Norse form <bjorn> and such.
But someone just showed me in a modern Polish dictionary the word
<bzik> and described a meaning for the word that sounds precisely the
same as e.g. the English "berserk." I said I thought this was a
modern loan, but thinking about that now, I have no reason to say
that. Does <berserk> to <bzik> follow any normal pattern for loans
from Germanic in Polish or Slavic in general? This would have to be
an older borrowing, wouldn't it, reflecting some changes since in
Polish itself? How old would those changes have to be? I find it
hard to believe that the two words are unconnected. Any help would
be appreciated.

Regards
Steve Long


etc.