Where does “Gilbertson” come from?

Gilbertson (English) comes from English gilbert, from Old French Gilbert, from Proto-Germanic gīslaz, from Proto-Germanic berhtaz, from Proto-Germanic hrabnaz, from Proto-Indo-European ḱorh₂-, from Proto-Indo-European ḱer-, from Proto-Indo-European kr̥- — army.

Ancestry of “Gilbertson”, step by step

Gilbertson traces back through two separate lines of ancestry.

via English gilbert

StepLanguageWordMeaning
1EnglishgilbertThe CGS unit of magnetomotive force equal to...
2Old FrenchGilbert
3Proto-Germanicgīslazhostage
4Proto-Germanicberhtazbright, shining
5Proto-Germanichrabnazraven
6Proto-Indo-Europeanḱorh₂-
7Proto-Indo-Europeanḱer-to grow, to make grow, to nourish; to plait,...
8Proto-Indo-Europeankr̥-to turn, to bend
9Proto-Indo-Europeanker-army

via English Sơn

StepLanguageWordMeaning
1EnglishSơn
2Middle Englishsoneson; soon; Alternative form of sonne
3Old Englishsōnaimmediately, at once
4Proto-West Germanicsān(ō)immediately
5Proto-Germanicsēna
6Proto-Germanic*sa
7Proto-Austronesian*əsa
8Proto-Oceanic*isa
Every word from Proto-Indo-European ker-