Where does “polar bear swim” come from?

polar bear swim (English) comes from English swim, from Middle English swime, from Old English swima, from Proto-West Germanic swimman, from Proto-Germanic swimmaną, from Proto-Indo-European swem(bʰ)- — to bend, turn, swing; to be unsteady, move, swim.

Ancestry of “polar bear swim”, step by step

polar bear swim traces back through two separate lines of ancestry.

via English swim

StepLanguageWordMeaning
1EnglishswimTo move through the water, without touching the...
2Middle Englishswime
3Old Englishswimaa swoon, swimming in the head
4Proto-West Germanicswimmanto swim
5Proto-Germanicswimmanąto be unsteady; to swim; float
6Proto-Indo-Europeanswem(bʰ)-to bend, turn, swing; to be unsteady, move, swim

via English polar bear

StepLanguageWordMeaning
1Englishpolar bearA very large bear, "Ursus maritimus" found in the...
Every word from Proto-Indo-European swem(bʰ)-Every word from Proto-Germanic swimmanąEvery word from Proto-West Germanic swimman