diameter

[dahy-am-i-ter]

noun

1. Geometry.

   1. a straight line passing through the center of a circle or sphere and meeting the circumference or surface at each end.

   2. a straight line passing from side to side of any figure or body, through its center.

2. the length of such a line.

3. the width of a circular or cylindrical object.

diameter

/ daɪˈæmɪtə /

noun

1. 1. a straight line connecting the centre of a geometric figure, esp a circle or sphere, with two points on the perimeter or surface

   2. the length of such a line

2. the thickness of something, esp with circular cross section

diameter

1. A straight line segment that passes through the center of a circle or sphere from one side to the other.

2. The length of such a line segment.

diameter

1. A straight line passing through the center of a figure, especially a circle or sphere, and joining two opposite points on its circumference.

Word History and Origins

Origin of diameter¹

First recorded in 1350–1400; Middle English diametre, from Old French, from Latin diametros, from Greek diámetros “diagonal, diameter,” from dia- dia- + -metros, derivative of métron meter ¹

Word History and Origins

Origin of diameter¹

C14: from Medieval Latin diametrus, variant of Latin diametros, from Greek: diameter, diagonal, from _dia- + metron measure

Example Sentences

By linking signals from these observatories, they effectively created a virtual telescope five times wider than Earth's diameter.

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Larger asteroids, those hundreds of meters or more in diameter, pose a much greater risk.

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Obesity typically causes a reduction in muscle fiber diameter, but green tea prevented this muscle atrophy.

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When the asteroid data is plotted on a graph of the rotation period versus diameter, something startling stands out - there's a gap, or dividing line that appears to split two distinct populations.

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Entrants choose their own stones and judges use a measuring device, the "ring of truth", to ensure they are no bigger than three inches in diameter.

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Related Words

• width