metalloid

/ˈmɛtəlɔɪd/
noun
  1. 1

    An element, such as silicon or germanium, intermediate in properties between that of a metal and a nonmetal; especially one that exhibits the external characteristics of a metal, but behaves chemically more as a nonmetal.

  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.

adjective
  1. 1

    Of or relating to the metalloids.

  2. 2

    Characteristic of the metal music genre.

Source: https://en.wiktionary.org/wiki/metalloid