Asymptotes

Part of speech: noun

Definitions

1. A point or line that a curve approaches but never reaches
2. a conceptual boundary that can describe limits in mathematical analysis
3. a reference in calculus indicating behavior of functions as they extend indefinitely

Etymology: Asymptotes is the plural of "asymptote," a term that came into English in the 17th century from Modern Latin "asymptotus," which was borrowed from Greek "asymptotos." The Greek adjective is built from "a-," meaning "not," and "syn," meaning "together," plus "ptotos," meaning "fallen" (from "piptein," "to fall"). Literally, it means "not falling together" or "not coinciding," a description of two things that never meet. The geometric sense comes from the Greek mathematician Apollonius of Perga, who wrote about conic sections around 200 BCE. He described lines that approach a curve without touching it, and the idea of two things that never meet was a natural way to name them. The Greek word was a mathematical description rather than a concrete image of falling, so the metaphor was already abstract by the time it reached English.