- noun an extremely thin metallic or semiconducting cylinder, capped at one end, consisting of a rolled-up layer of fullerene-structured carbon atoms
- Fullerene that is arranged into a cylindrical shape. It is many times stronger and much lighter than steel, and depending on various factors may be a semiconductor, conductor, or superconductor. Used, for instance, as conducting paths between circuit components on a nanometer scale. Also called buckytube.