The compound adjective "ten-week" is a transparent modern English formation, combining the cardinal number "ten" with the noun "week." The number "ten" traces its lineage back to the Proto-Indo-European root 'déḱm̥t', a fundamental numeral that evolved consistently into the Germanic 'tehun' and Old English 'tīen'. The term "week" originates from a Germanic concept of change or turning, as seen in Proto-Germanic 'wikōn', referring to the succession or cycle of days. The straightforward compounding of these two ancient roots creates a precise temporal descriptor, literally meaning "of ten weeks," which illustrates the analytical nature of English in forming specific compound modifiers.

Structure: ten (number) + week (period of time) - ten: From Old English 'tīen', from Proto-Germanic 'tehun', from Proto-Indo-European 'déḱm̥t'. Functions as a numerical root. - week: From Old English 'wice', 'wicu' ("a turning" or "succession"), from Proto-Germanic 'wikōn' ("a turn" or "change"), likely related to the concept of change or succession of days. Functions as a noun root denoting a standard time period.