from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Strong; vehement.
- adv. Quickly, speedily, promptly.
- adv. Strongly; vehemently; very.
from The Century Dictionary and Cyclopedia
- Strong: used only in the comparative swither, in the phrases swither hand, the right hand, swither half, the right side.
- Quickly; speedily; promptly.
- Strongly; very.
- Interjectionally, quick! off! begone?
From Middle English, from Old English swīþ ("strong, mighty, powerful, active, severe, violent"), 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")), Dutch gezwind ("fast, quick, swift"), Old Norse svinnr, Gothic 𐍃𐍅𐌹𐌽𐌸𐍃 (swinþs, "strong"). Related to sound. (Wiktionary)
From Middle English swith, swithe, from Old English swīþe ("very much, exceedingly, severely, violently, fiercely"), from Proto-Germanic *swinþa (“strongly”), from Proto-Indo-European *swento- (“active, healthy”). (Wiktionary)