Definition of sphere

The word "sphere" originated from the Greek word "sphaira" (σφαιρα), which means "ball" or "globular shape". This Greek word is derived from "spharros" (σφάρρος), meaning "globular" or "bolus". The term "sphere" was first used in English in the 14th century to describe a geometric shape, specifically a three-dimensional ball. Over time, the word expanded to include notions of scope, influence, and domain, as in "spheres of influence" or "social spheres". In modern usage, the word "sphere" is often used to describe a broad area of activity, interest, or expertise, such as the "sphere of astronomy" or the "sphere of politics". Despite its evolution, the word's core meaning remains rooted in its ancient Greek origins as a reference to a three-dimensional ball.