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

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.

From BBC

Among the munitions were dozens of thick, green plastic discs about the diameter of a saucer.

From BBC

Captain Nathan Davies, a commercial airline pilot, says: "I have noticed more large storm cells spreading 80 miles plus in diameter in the last few years, something you'd expect to be rare."

From BBC

In 2022, authorities discovered a similar tunnel under Otay Mesa that was roughly 1,750 feet long, 60 feet deep and 4 feet in diameter with reinforced walls and a rail system.

From Los Angeles Times

The round table is 14 feet in diameter to accommodate all the players.

From Los Angeles Times

Related Words

• width