Etymology : Middle English diametre, from Middle French, from Latin diametros, from Greek, from dia- + metron measure; more at MEASURE
Pronunciation : dI-'a-m&-t&r
Function : noun
Date : 14th century
1. length of a central line which extends from one side of an object to its opposite side. diameter\di*am"e*ter\ , n. [f. diamètre, l. diametros, fr. gr. ; dia` through + measure. see:
meter.].
2. (geom.) (a) any right line passing through the center of a figure or body, as a circle, conic section, sphere, cube, etc., and terminated by the opposite boundaries; a straight line which bisects a system of parallel chords drawn in a curve. (b) a diametral plane.
3. the length of a straight line through the center of an object from side to side; width; thickness; as, the diameter of a tree or rock.note: in an elongated object the diameter is usually taken at right angles to the longer axis.
4. (arch.) the distance through the lower part of the shaft of a column, used as a standard measure for all parts of the order. see:
module.
5. Any right line passing through the center of a figure or body, as a circle, conic section, sphere, cube, etc., and terminated by the opposite boundaries; a straight line which bisects a system of parallel chords drawn in a curve.
6. A diametral plane.
7. The length of a straight line through the center of an object from side to side; width; thickness; as, the diameter of a tree or rock.
8. The distance through the lower part of the shaft of a column, used as a standard measure for all parts of the order.
9. See Module. the length of a straight line passing through the center of a circle and connecting two points on the circumference a straight line connecting the center of a circle with two points on its perimeter.
10. The diameter of a round object is the length of a straight line that can be drawn across it, passing through the middle of it. a tube less than a fifth of the diameter of a human hair. a straight line from one side of a circle to the other side, passing through the centre of the circle, or the length of this line 3 inches/1 metre etc in diameter (diametre, from diametros , from metron ).