The phrase "turn of the century" emerged in the late 19th century as a descriptive term for the period around the year 1900, marking the transition from the 1800s to the 1900s. It is built from common English words: "turn" (from Old English tyrnan, meaning to revolve or change direction), "of", "the", and "century" (from Latin centuria, via Old French, meaning a period of one hundred years). The logic of the phrase is metaphorical, conceptualizing the passage of time as a turning point, much like the turning of a page or a corner. While now often used generically for any century change, its most iconic and frequent reference remains to the culturally rich era spanning the late 1890s to early 1900s, characterized by technological innovation and artistic change.

This is a fixed compound adjective formed from a complete prepositional phrase. It is not productively segmented into smaller, independent morphemes for analysis. Its meaning derives from the entire idiomatic unit.