Where does “Untertagebau” come from?

Untertagebau (German) comes from German Tagebau, from German tag, from German guten Tag, from Alemannic German Tag, from Middle High German tac, from Old High German tag, from Proto-West Germanic dag, from Proto-Germanic dagaz — to burn; warm, hot.

Untertagebau (German): underground mining

Definitions

  1. underground mining

Ancestry of “Untertagebau”, step by step

Untertagebau traces back through two separate lines of ancestry.

via German Tagebau

StepLanguageWordMeaning
1GermanTagebauopen-pit mining, opencast mining; opencast mine
2Germantagsingular imperative of tagen
3Germanguten Taghello, good day, good afternoon
4Alemannic GermanTagday
5Middle High GermantacAlternative form of tag
6Old High Germantagday
7Proto-West Germanicdagday
8Proto-Germanicdagazday; name of the D-rune
9Proto-Indo-Europeandʰegʷʰ-to burn; warm, hot

via German unter

StepLanguageWordMeaning
1Germanunterunder; below; among, between
2Middle High Germanunder—
3Old High Germanuntarunder
4Proto-Germanicunderamong, between; under, beneath; under
5Proto-Indo-Europeanh₁entérbetween
6Proto-Indo-Europeanh₁enin; in, inside
Every word from Proto-Indo-European dʰegʷʰ- →Every word from Proto-Germanic dagaz →Every word from Proto-West Germanic dag →