Illustration of polyhedron
polyhedron
noun
poly·he·dron ˌpä-lē-ˈhē-drən 
plural polyhedrons or polyhedra ˌpä-lē-ˈhē-drə
: a solid formed by plane faces
polyhedral
ˌpä-lē-ˈhē-drəl
adjective 
Example Sentences
Recent Examples on the Web Euler implicitly assumed his polyhedra were convex, meaning a line segment joining any two points stayed completely within the polyhedron. 
quantamagazine.org, 26 Jan. 2021 This polyhedron is a classic prism made from professional-grade optical crystal glass. Popular Science, 23 Oct. 2019 The 20th-century mathematician Aleksandr Aleksandrov proved that for every two-dimensional polygon, there is one unique way of folding it to form a 3-D polyhedron. Quanta Magazine, 5 Jan. 2017 And the circle packing proof tells you that there’s a polyhedron that has all its edges tangent to a sphere. Quanta Magazine, 19 Mar. 2018 The printer cranks out up to 150 polyhedra each year – everything from models of protein crystallography to Mars' topography. Stacey Smith Lang, WIRED, 1 Nov. 2001
quantamagazine.org, 26 Jan. 2021 This polyhedron is a classic prism made from professional-grade optical crystal glass. Popular Science, 23 Oct. 2019 The 20th-century mathematician Aleksandr Aleksandrov proved that for every two-dimensional polygon, there is one unique way of folding it to form a 3-D polyhedron. Quanta Magazine, 5 Jan. 2017 And the circle packing proof tells you that there’s a polyhedron that has all its edges tangent to a sphere. Quanta Magazine, 19 Mar. 2018 The printer cranks out up to 150 polyhedra each year – everything from models of protein crystallography to Mars' topography. Stacey Smith Lang, WIRED, 1 Nov. 2001 Word History
Etymology
borrowed from Greek polýedron, from poly- poly- + -edron -hedron
Note: The Greek word is attested in Euclid's Elementa, Book 12, Proposition 17.
First Known Use
1570, in the meaning defined above