Quincentennial

Part of speech: noun

Definitions

1. A 500th anniversary celebration or commemoration of a significant event
2. A special occasion marking five hundred years since a notable event occurred
3. The observance or remembrance of an event's 500-year milestone

Etymology: "Quincentennial" is a compound built from two Latin-derived parts. The first, "quin-", comes from Latin "quinque", meaning "five," and appears in English words like "quintet" and "quintuplet." The second part, "centennial," is itself an English formation from the Latin "centum," "hundred," with a suffix that marks something as relating to a hundred years. Put together, the word means a five-hundredth anniversary, a span of five centuries. The compound follows the pattern of "centennial," the older word for a hundredth anniversary, so "quincentennial" simply extends that model to five hundred years. Its Latin cousin "quingenti," meaning "500," shows the same five-and-hundred arithmetic in its own grammar. English speakers thus built the term by adding a numerical prefix to an existing word, without needing any single earlier source for the whole.