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What is Lapp?
The word Lapp can be traced to Old Swedish lapper, Icelandic lappir (plural) of Finnish origin; compare Finnish lappalainen Lapp, Lappi Lapland
What does Lapp mean?
Possibly meaning wilderness in the north, the original meaning of Lapp is unknown.
Are there any other interesting aspects about the Sami people article?
The Sámi are often known in other languages by the exonyms Lap, Lapp, or Laplanders, although these are considered derogatory terms, while others accept at least the name Lappland

Question: Who was Johannes?
Self-contained rewrite: Who was Johannes Schefferus?