Hedra
/ˈhɛdrə/noun
The plural of hedron, referring to the faces or sides of geometric solids.
Did you know?The same Greek root survives in “cathedral,” originally referring to the bishop’s seat, linking sacred architecture and geometric language through the idea of a seat or base.
Etymological Timeline
Proto-Indo-European
PIE
*sed-
“To sit or settle in a place”
Ancient Greek
Greek
ἕδρα (hedra)
“Seat, sitting place, base, or surface”
Ancient Greek
Greek
ἕδραι (hedrai)
“Seats, bases, or surfaces; the plural form”
Late Antiquity
Greek/Latin
-hedron / -hedra
“A combining form referring to a solid’s base or face”
17th Century
English
hedron
“A geometrical solid, especially one considered by its faces”
Modern English
English
hedra
“Plural of hedron: the faces or sides of geometric solids”