Where does “Nackenwirbel” come from?

Nackenwirbel (German) comes from German Wirbel, from Middle High German wirbel, from Old High German wirbil, from Proto-Germanic hwirbilaz, from Proto-Germanic -ilaz, from Proto-Indo-European -lós — Forms agent nouns from verbal roots.

Ancestry of “Nackenwirbel”, step by step

Nackenwirbel traces back through two separate lines of ancestry.

via German Wirbel

StepLanguageWordMeaning
1GermanWirbelwhirl; whorl; vortex
2Middle High Germanwirbel—
3Old High Germanwirbil—
4Proto-Germanichwirbilazcircle, ring, whirl
5Proto-Germanic-ilazagent suffix; diminutive suffix
6Proto-Indo-European-lósForms agent nouns from verbal roots

via German Nacken

StepLanguageWordMeaning
1GermanNackennape of the neck
2Middle High Germannacke—
3Proto-Germanichnakkôthe back of the neck; nape
4Proto-Indo-Europeanknog-back of the head, nape, neck
5Proto-Indo-Europeanken-to arise, begin
Every word from Proto-Indo-European -lós →Every word from Proto-Germanic -ilaz →Every word from Proto-Germanic hwirbilaz →