Where does “undertrousers” come from?

undertrousers (English) comes from English trousers, from English trouzes, from English trouse, from Irish triús, from Middle Irish triubus, from Old Irish trebus, from Old French trebus, from Late Latin tubrucus — to shine, shimmer.

undertrousers (English): with long legs

Definitions

  1. with long legs

Ancestry of “undertrousers”, step by step

undertrousers traces back through two separate lines of ancestry.

via English trousers

StepLanguageWordMeaning
1EnglishtrousersAn article of clothing that covers the part of...
2Englishtrouzes
3Englishtrousebrushwood; trousers
4Irishtriústrousers, trews
5Middle Irishtriubus
6Old Irishtrebus
7Old Frenchtrebus
8Late Latintubrucus
9Proto-Germanic*þeuhabrōksloincloth
10Proto-Indo-Europeanbʰrēǵ-to shine, shimmer

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 bʰrēǵ-Every word from Proto-Germanic *þeuhabrōksEvery word from Late Latin tubrucus