D defs.my
Entry 3 senses Webster, 1913

Diameter

/dī-ăm'ĭtər/ · Di·am·e·ter · IPA /daɪˈæmɪdɚ/
01 n. Any right line passing through the center of a figure or body, as a circle, conic section, sphere, cube, etc., and terminated by the opposi…
  1. 1.
    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.(Geom.)
  2. 2.
    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.
  3. 3.
    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.(Arch.) See: Module
Phrases & compounds
Conjugate diameters — See under Conjugate.