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English definition of “diameter”

diameter

noun [C or U]     /daɪˈæm.ɪ.tər/ US  /-ə.t̬ɚ/
(the length of) a straight line that reaches from one point on the edge of a round shape or object, through its centre, to a point on the opposite edge: The diameter measures twice the radius. The pond is six feet in diameter.Parts of geometrical shapes
(Definition of diameter noun from the Cambridge Advanced Learner's Dictionary & Thesaurus © Cambridge University Press)
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