metalloid

Short definition from Wiktionary

Noun

1. 1
   An element, such as silicon or germanium, intermediate in properties between that of a metal and a nonmetal; especially an elemental semiconductor.
2. 2
   The metallic base of a fixed alkali, or alkaline earth; applied to sodium, potassium, and some other metallic substances whose metallic character was supposed to be not well defined.
3. 3
   A nonmetal.

Adjective

1. 1
   Of or relating to the metalloids.
2. 2
   Characteristic of the metal music genre.