noun
diameter
deye-A-mih-tuh
noun
1
A straight line passing through the center of a circle, connecting two points on its edge; also, the length of that line.
"The pipe has a diameter of about ten centimeters."
"The planet's diameter is roughly four times that of Earth's moon."
How to Use Diameter
Learner’s notesIn plain EnglishThe distance straight across a circle, through its middle — twice the radius.
Common pairings
measure the diameter
a diameter of
inner diameter
Word Forms
diameters plural
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The pipe has a _____ of about ten centimeters.
Etymology
From Greek diametros ("line measuring across"), from dia- ("across") + metron ("measure").