Where does “Elsterian” come from?

Elsterian (English) comes from English Elster, from German Elster, from Middle High German elster, from Old High German agalstra, from Proto-West Germanic agastrijā, from Proto-West Germanic ag-ad- ~ ag-at-, from Proto-West Germanic agu, from Proto-Germanic agō — sharp.

Elsterian (English): Of or relating to the Elster glaciation/Elsterian glaciation

Definitions

  1. Of or relating to the Elster glaciation/Elsterian glaciation

Ancestry of “Elsterian”, step by step

Elsterian traces back through two separate lines of ancestry.

via English Elster

StepLanguageWordMeaning
1EnglishElster—
2GermanElstermagpie
3Middle High Germanelster—
4Old High Germanagalstra—
5Proto-West Germanicagastrijāmagpie
6Proto-West Germanicag-ad- ~ ag-at-—
7Proto-West Germanicagumagpie
8Proto-Germanicagō—
9Proto-Indo-Europeanh₂oḱ-éh₂—
10Proto-Indo-Europeanh₂eḱ-sharp

via English ian

StepLanguageWordMeaning
1Englishian—
2IrishEoinJohn any of several people in the Bible
3Old IrishIohainJohn apostle
4LatinIōannēsJohn biblical persons
5Ancient GreekἸωάννης—
6HebrewיוחנןYahweh is gracious
7Hebrewחנוןgracious, merciful, compassionate; passive...
8Moroccan Arabicخنونةmucus, snot
9Arabicخُنَّة—
Every word from Proto-Indo-European h₂eḱ- →Every word from Proto-Indo-European h₂oḱ-éh₂ →Every word from Proto-Germanic agō →