centuries-old

the compound "centuries-old" is a modern english formation that transparently combines two established words to denote great age. the first element, "century", entered english via old french centurie from latin centuria, which itself derives from the proto-indo-european root ḱm̥tóm (hundred), originally a military term for a division of one hundred soldiers. the second element, "old", descends from the proto-germanic aldaz, related to the concept of growth and adulthood from the pie root h₂el- (to grow, nourish). the logic of the compound is direct and descriptive, using the concrete measure of "centuries" to intensify the abstract quality of being "old", creating a term that evokes historical depth and tradition.

this is a compound adjective formed from the plural noun "centuries" and the adjective "old". "century" originates from latin centuria (a group of one hundred, a division of a roman legion), from centum (hundred). "old" comes from old english eald, from proto-germanic aldaz.