The word 'upsweep' is a transparent compound formed within Modern English from two native Germanic elements. The first element, 'up', derives from the Old English preposition/adverb 'up', which has cognates across Germanic languages and traces back to the Proto-Indo-European root upo, meaning 'under, up from under'. The second element, 'sweep', originates from the Old English verb 'swāpan', meaning 'to sweep, drive, rush', likely from a Proto-Germanic root. The compound logically combines these concrete directional and motional concepts to describe the specific action of sweeping upward or the resulting upward-curved shape, a process typical of English's ability to create new, descriptive terms from its existing lexical stock.

Structure: up (direction) + sweep (motion) - up: Old English origin, functioning as an adverb or prefix denoting an upward direction or movement. - sweep: Old English origin (swāpan), functioning as a verb or noun denoting a continuous, curving motion.