Where does “underrealm” come from?

underrealm (English) comes from English realm, from Middle English rewme, from Old French reaume, from Old French real, from Old French regiel, from Latin regalis, from Latin rex, from Proto-Italic rēks — to straighten, to right oneself; right; just.

underrealm (English): An underground realm; an underworld

Definitions

  1. An underground realm; an underworld

Ancestry of “underrealm”, step by step

underrealm traces back through two separate lines of ancestry.

via English realm

StepLanguageWordMeaning
1EnglishrealmAn abstract sphere of influence, real or...
2Middle Englishrewmekingdom, realm, nation; region, area, province;...
3Old Frenchreaumekingdom
4Old Frenchrealroyal; Alternative form of roial
5Old Frenchregiel
6Latinregalisregal, royal; of or pertaining to a king
7Latinrexking, ruler; despot, tyrant; king
8Proto-Italicrēksking
9Proto-Indo-Europeanh₃rḗǵsking, ruler
10Proto-Indo-Europeanh₃reǵ-to straighten, to right oneself; right; just

via English under

StepLanguageWordMeaning
1EnglishunderIn or at a lower level than; As a subject of;...
2Middle Englishunderunder
3Old Englishunderunder, beneath
4Proto-Germanicunderamong, between; under, beneath; under
5Proto-Indo-Europeanh₁entérbetween
6Proto-Indo-Europeanh₁enin; in, inside
Every word from Proto-Indo-European h₃reǵ-Every word from Proto-Indo-European h₃rḗǵsEvery word from Proto-Italic rēks