diameter

Etymology

From Old French diametre (French diamètre), from Latin diametrus, from Ancient Greek διάμετρος (diámetros) (γραμμή (grammḗ)) (diametros grammē, “line measuring across”), from διά (diá, “across”) + μέτρον (métron, “measure”).

noun

1. (geometry) Any straight line between two points on the circumference of a circle that passes through the centre/center of the circle.
2. (geometry) The length of such a line.
3. (geometry) The maximum distance between any two points in a metric space
4. (graph theory) The maximum eccentricity over all vertices in a graph.