Part of speech: adverb
(compar swíþor; superl swíþost) 1. very much, greatly; exceedingly; 2. superl (swíþost) mostly, chiefly; especially (also swíðe, swýþe, swýðe)
Etymology
[Mod E SWITH arch, dial “strongly; greatly; rapidly“; ← swíþ, swíð a “strong, vehement”; O Fris swīthe; O Sax swītho; MHG swinde “rapidly, quickly”; Mod G adv, a (ge)schwind]