any of a class of hollow, tube-shaped or ball-shaped molecules consisting of 32 or more carbon atoms, that have extraordinary strength and stability
See fullerene in American Heritage Dictionary 4
(fo͝olˈə-rēnˌ)
noun
Any of various cagelike, hollow molecules composed of hexagonal and pentagonal groups of atoms, and especially those formed from carbon, that constitute the third form of carbon after diamond and graphite.