The compound 'time-series' is a modern technical term formed by combining two fundamental nouns of English. The first element, 'time', originates from the Old English concept of a measured interval, a cornerstone of Germanic temporal understanding. The second, 'series', entered English via Latin, carrying the classical notion of a linked sequence or row. Their union in the 19th century created a precise descriptor for statistics and economics, logically denoting a sequence where the linking principle is chronological order. Thus, the term literally means "a succession linked by time," perfectly capturing its function of tracking how a variable changes over measured intervals.

Structure: time (temporal measure) + series (sequence) - time: From Old English 'tīma', meaning a period, season, or point of duration. It is a Germanic word of uncertain ultimate origin, functioning as a noun denoting a measurable period. - series: From Latin 'seriēs', meaning a row, chain, or succession, derived from the verb 'serere' (to join, link). It functions as a noun denoting a connected sequence.