An Etymological Dictionary of Astronomy and Astrophysics

A combining form meaning “face” used in the names of geometrical solid figures having the form or number of faces specified by the initial element.

Etymology (EN): N.L., from Gk -edron, from hedra “seat, base, chair, face of a geometric solid,” from PIE root *sed- “to → sit.”

Etymology (PE): Dimé, from dim, → face.