boron

noun2

1. •
   The chemical element (symbol B) with an atomic number of 5, which is a metalloid found in its pure form as a dark amorphous powder.

   • The B₆-type octahedral borons are each bonded to five other boron atoms; four are part of the same octahedron, and one is external to this octahedron. — 1976
2. •
   An atom of this element.