icosahedron (English)
Where does "icosahedron" come from?
The word icosahedron traces its origins to the Ancient Greek term eikosáedron, a compound formed by combining eíkosi, meaning 'twenty,' with hédra, which refers to a seat or face. This descriptive construction was adopted into English as a technical name for any polyhedron featuring twenty faces, highlighting the mathematical beauty of its Greek roots.
Full etymology tree
- icosahedron (English), 'A polyhedron with twenty faces.'
- borrowed εἰκοσάεδρον (eikosáedron) (Ancient Greek)
- compound εἴκοσι (eíkosi) (Ancient Greek), 'twenty'
- inherited *h₁wídḱm̥ti (Proto-Indo-European)
- compound ἕδρα (hédra) (Ancient Greek), 'seat, chair, stool, bench'
- inherited *sedreh₂ (Proto-Indo-European)
- derived *sed- (Proto-Indo-European), 'to sit'
- inherited *sedreh₂ (Proto-Indo-European)
- compound εἴκοσι (eíkosi) (Ancient Greek), 'twenty'
- borrowed εἰκοσάεδρον (eikosáedron) (Ancient Greek)
Updated June 2026
Etymology data from Wiktionary, CC BY-SA 4.0 · About Miraris