Where does “underhammer” come from?

underhammer (English) comes from English Hammer, from Middle English hamer, from Old English hamor, from Proto-West Germanic *hamar, from Proto-Germanic hamaraz, from Proto-Indo-European h₂eḱmoros, from Proto-Indo-European h₂éḱmō, from Proto-Indo-European h₂eḱ- — sharp.

underhammer (English): A firing mechanism where the hammer is mounted...

Definitions

  1. A firing mechanism where the hammer is mounted...

Ancestry of “underhammer”, step by step

underhammer traces back through two separate lines of ancestry.

via English Hammer

StepLanguageWordMeaning
1EnglishHammersomeone connected with West Ham Football Club, as...
2Middle EnglishhamerA hammer; A fierce individual; one with strong...
3Old Englishhamorhammer
4Proto-West Germanic*hamar
5Proto-Germanichamarazhammer
6Proto-Indo-Europeanh₂eḱmoros
7Proto-Indo-Europeanh₂éḱmōstone
8Proto-Indo-Europeanh₂eḱ-sharp

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 h₂eḱ-Every word from Proto-Indo-European h₂éḱmōEvery word from Proto-Indo-European h₂eḱmoros