noun \dī-ˈa-mə-tər\

: a straight line from one side of something (such as a circle) to the other side that passes through the center point

: the distance through the center of something from one side to the other

Full Definition of DIAMETER

:  a chord passing through the center of a figure or body
:  the length of a straight line through the center of an object
:  a unit of enlargement used with a number to indicate magnification by a lens or optical system <an object one millimeter wide magnified 40 diameters appears 40 millimeters wide>
di·am·e·tral \-ˈa-mə-trəl\ adjective

Examples of DIAMETER

  1. The dotted line indicates the diameter of the circle.
  2. What is the diameter of the tree trunk?
  3. Dig a hole that's two feet deep and three feet in diameter.

Origin of DIAMETER

Middle English diametre, from Middle French, from Latin diametros, from Greek, from dia- + metron measure — more at measure
First Known Use: 14th century

Other Mathematics and Statistics Terms

abscissa, denominator, divisor, equilateral, exponent, hypotenuse, logarithm, oblique, radii, rhomb


noun \dī-ˈam-ət-ər\   (Medical Dictionary)

Medical Definition of DIAMETER

: a unit of magnification for an optical instrument equal to the number of times the linear dimensions of an object are apparently increased <a microscope magnifying 60 diameters>
: one of the maximal breadths of a part of the body <the transverse diameter of the inlet of the pelvis>


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