forty-year

The compound "forty-year" is a modern English formation combining two ancient Germanic elements. "Forty" descends from the Old English "féowertig", a compound itself of "féower" (four) and "tig" (a group of ten), reflecting the base-ten counting system. "Year" originates from the Proto-Germanic "jērą", related to cycles and seasons. When combined in the hyphenated adjectival form, these morphemes create a precise temporal descriptor, literally meaning "of or pertaining to a span of forty years", used to quantify duration, experience, or anniversaries.

Structure: forty (number) + year (time period) forty: From Old English féowertig, meaning "four tens". Its functional role is as a numeral quantifier. year: From Old English gēar, meaning "year, cycle of seasons". Its functional role is as a noun specifying the unit of time.