Where does “unbrother” come from?

unbrother (English) comes from English brother, from Middle English brother, from Old English brōþor, from Proto-West Germanic brōþer, from Proto-Germanic brōþēr, from Proto-Indo-European bʰréh₂tēr — brother.

unbrother (English): To make no longer a brother; to expel from a brotherhood

Definitions

  1. To make no longer a brother; to expel from a brotherhood

Ancestry of “unbrother”, step by step

unbrother traces back through two separate lines of ancestry.

via English brother

StepLanguageWordMeaning
1EnglishbrotherSon of the same parents as another person; A male...
2Middle EnglishbrotherA brother or brother-in-law; a male sibling
3Old Englishbrōþorbrother
4Proto-West Germanicbrōþerbrother
5Proto-Germanicbrōþērbrother
6Proto-Indo-Europeanbʰréh₂tērbrother

via English un

StepLanguageWordMeaning
1EnglishunOne
Every word from Proto-Indo-European bʰréh₂tērEvery word from Proto-Germanic brōþērEvery word from Proto-West Germanic brōþer