Diameters

Part of speech: noun

Definitions

1. A straight line that passes from side to side through the center of a circle or sphere and its measure
2. a thorough measurement spanning the width of an object or feature, often applied in various geometrical contexts
3. the distance across a circular or cylindrical shape, linking two points on its periphery through the center point

Etymology: "Diameters" is the plural of "diameter", a word that Greek mathematicians built from two ordinary pieces: "dia", meaning "across" or "through", and "metron", meaning "measure". The full Greek phrase was "diametros grammē", a "line measuring across", which described the straight line running through the centre of a circle from one edge to the other. The name thus described what the line did, rather than naming a thing. The word passed into Latin as "diametros" and then into Old French as "diametre" before reaching English. Its meaning has stayed remarkably stable across all those languages: a measurement taken straight across, from one side of a shape to the other.

Synonyms: widths, thicknesses, radii