Every Monday we will post an entry that hasn’t yet been published with a view towards harnessing the collective onomastic power of the internet. If you have any thoughts about the name’s origin, other variants it might be related to, other examples of its use, etc., please share them in the comments! If you wish to browse other Mystery Monday names, there is an index.
It’s always fun to come back to “Z” in our trips through the alphabet! We’ve got more Z-names than you might think.
This one is found in Mecklenburg in the 13th C. The context doesn’t make it 100% certain that it’s a given name, rather than a byname, but on balance it’s more likely to be a given name than not, and that’s why we have it included in a provisional entry in the Dictionary. Someday we may learn more info that means we’ll jettison it — perhaps even from this post! — but we’d always rather collect more false positives rather than miss out on tasty tasty name gobbits.
So, what are your thoughts? Do you recognise it? Is it a given name or a byname? Let us know in the comments! We’d love to hear.
Dictionary of Medieval Names from European Sources 
According to the snippet of p. 161 of Deutsch-Slawische Forschungen zur Namenkunde und Siedlungsgeschichte, Issue 32, visible here, the name is Slavic, from Old Slavic zaviděti ‘to envy’, which is apparently a calque of Latin invidēre ‘to envy’; the second element is from vìděti ‘to see’. The personal name is old enough that it is found in the placename Zauiztorp 1230, villa Zauiz 1230 (now Saunstorf in Germany).