Germanic UFOs

UFOs are real! No, I'm not talking about extraterrestrials or little green men. I'm talking about lexical items in Germanic that have unknown origins. Since the advent of modern Germanic studies, linguists have speculated as to the percentage of lexemes of unknown origins. The reason why this is interesting is that the Germanic language was an "invasive" language, replacing the native indigenous languages of Scandinavia that have since disappeared. Many of these unknown words may in fact be vestigial loanwords from the aboriginal tongues. 

But how many Proto-Germanic lexemes are of unknown etymology? Accounts vary very widely....

  • Theo Vennemann: Up to 50%
  • Guus Kroonen: ~15%
  • Sigmund Feist: 33%

We live in a world of uncertainty, folks.