Where does “bolster” come from?

bolster (Old Swedish) comes from Old Norse bulstr, from Proto-Germanic bulstraz, from Proto-Indo-European bʰelǵʰ-, from Proto-Indo-European bʰel-, from Proto-Indo-European bʰōl-.

Ancestry of “bolster”, step by step

bolster traces back through two separate lines of ancestry.

via Old Norse bulstr

StepLanguageWordMeaning
1Old Norsebulstr
2Proto-Germanicbulstrazbolster, pillow, cushion
3Proto-Indo-Europeanbʰelǵʰ-to swell
4Proto-Indo-Europeanbʰel-to sound; to speak, roar, bark; shiny, white; to...
5Proto-Indo-Europeanbʰōl-

via Old Norse bólstr

StepLanguageWordMeaning
1Old Norsebólstrbolster, pillow
Every word from Proto-Indo-European bʰōl-Every word from Proto-Indo-European bʰel-Every word from Proto-Indo-European bʰelǵʰ-