swith

From Middle English swith, from Old English swīþ (“strong, mighty, powerful, active, severe, violent”), from Proto-West Germanic *swinþ, from Proto-Germanic *swinþaz (“strong”), from Proto-Indo-European *swento- (“active, healthy”).
Cognate with Old Saxon swīth, Middle High German swind (Modern German geschwind (“fast, quick, swift”)), Middle Low German swîde (Modern Low German swied (“very, quite”)), Dutch gezwind (“fast, quick, swift”), West Frisian swiid (“impressive, special”), Old Norse svinnr, sviðr (“quick, clever, understanding, wise”), Gothic 𐍃𐍅𐌹𐌽𐌸𐍃 (swinþs, “strong”). Related to sound.