diameter

American  

[dahy-am-i-ter] / daɪˈæm ɪ tər /

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.

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diameter British  

/ 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

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diameter Scientific  

/ dī-ăm′ĭ-tər /

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.

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diameter Cultural  

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

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Etymology

Origin of diameter

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

Example Sentences

The shape, “surrounded by a semi-circle of light about eighteen inches in diameter,” formed itself into what looked like a human head.

From Literature

They are considered harmless to humans and are predominantly found sitting in large webs often more than a metre in diameter.

From BBC

The prizes have a diameter of just over 3 inches and are less than half an inch thick.

From The Wall Street Journal

The device measures approximately 10 cm in diameter and 30 cm long and has a red anodised finish.

From BBC

The cost for treating oak wilt, or any tree disease that requires a fungicide injection, depends on the tree’s diameter at breast height, or DBH.

From The Wall Street Journal

Related Words

• width