Where does “underarm” come from?

underarm (Danish) comes from Danish under, from Old Norse undir, from Proto-Germanic under, from Proto-Indo-European h₁entér, from Proto-Indo-European h₁en — in; in, inside.

underarm (Danish): forearm

Definitions

  1. forearm

Ancestry of “underarm”, step by step

underarm traces back through two separate lines of ancestry.

via Danish under

StepLanguageWordMeaning
1Danishunderunder; underneath; below
2Old Norseundirunder, underneath
3Proto-Germanicunderamong, between; under, beneath; under
4Proto-Indo-Europeanh₁entérbetween
5Proto-Indo-Europeanh₁enin; in, inside

via Danish arm

StepLanguageWordMeaning
1Danisharmarm; poor, not rich; unfortunate, poor
2Old Norsearmrarm; poor, unhappy; wretched, wicked
3Proto-Germanicarmazarm; poor, miserable; pitiful, pitiable
4Proto-Indo-Europeanh₂ermos—
5Proto-Indo-Europeanh₂er-to fit, to fix, to put together
Every word from Proto-Indo-European h₁en →Every word from Proto-Indo-European h₁entér →Every word from Proto-Germanic under →
underarm — Etymology, Origin & Word History | Etymology Explorer