Definition of "fullerene" [fullerene]

• 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. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "The world known as Virga is a fullerene balloon 3,000 kilometers in diameter, filled with air, water, and aimlessly floating chunks of rock."
• "If you have a many-layered fullerene ball, structured like an onion, it approaches the density of graphite."
• "The world of Virga is a huge fullerene balloon dotted with artificial suns that light up nations which, in turn, are populated by towns."