A straight line passing from side to side through the centre of a body or figure, especially a circle or sphere
the mill wheel is eight feet in diameter
The outer or larger diameter of an object, especially a screw thread.
Having or adaptable to a variety of diameters.
The diameter of the pitch circle of a cogwheel, gear, etc.
The diameter of a planet measured from pole to pole.
The apparent diameter of a planet or other celestial object measured by the angle which it subtends at the point of observation
The distance between the front and rear of the pelvis