oc·​ta·​he·​dron | \ ˌäk-tə-ˈhē-drən How to pronounce octahedron (audio) \
plural octahedrons or octahedra\ ˌäk-​tə-​ˈhē-​drə How to pronounce octahedra (audio) \

Definition of octahedron

: a solid bounded by eight plane faces

Illustration of octahedron

Illustration of octahedron

Examples of octahedron in a Sentence

Recent Examples on the Web

They are defined by symmetry, and the Greeks knew that there were only five possibilities meeting the criteria: the tetrahedron, cube, octahedron, dodecahedron and icosahedron. Eugenia Cheng, WSJ, "Lessons of the Möbius Bagel," 10 Aug. 2017 Diamonds, which form eight-sided crystals called octahedrons, can be billions of years old, Dr. Harlow said. C. Claiborne Ray, New York Times, "Are Diamonds Really Forever?," 12 June 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'octahedron.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of octahedron

1570, in the meaning defined above

History and Etymology for octahedron

Greek oktaedron, from okta- + -edron -hedron

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Time Traveler for octahedron

The first known use of octahedron was in 1570

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More from Merriam-Webster on octahedron

Britannica.com: Encyclopedia article about octahedron

Comments on octahedron

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one from the Upper Peninsula of Michigan

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