Periods

Part of speech: noun

Definitions

1. Segments of time marked by a beginning and end, often used to describe phases in history or events ; recurring biological cycles experienced by females involving bleeding from the uterus
2. Intervals of time during which specific events occur, such as school terms or geological eras ; the monthly natural process in which the female body sheds the uterine lining
3. Designated spans of time used to organize activities or historical phases ; the regular monthly bleeding cycle indicating fertility status in females

Etymology: In ancient Greek, "periodos" meant a circuit or a going around, built from "peri" (around) and "hodos" (way). Greek writers used it for the orbit of a heavenly body and for a rounded sentence, one that carried its meaning through to a complete close. That idea of a unit that comes full circle is why English uses the same word for the mark that ends a sentence. The Latin "periodus" came into English through Old French "periode" in the Middle English period. The sense of a span of time between two points grew from the notion of a completed cycle, and the word later came to name the phases of history. The bodily sense, a recurring cycle of bleeding, is a later extension of the same idea of a regular circuit that returns to its starting point.

Synonyms: phases, stages, epochs, intervals