/met"l oyd'/ , n.
1. a nonmetal that in combination with a metal forms an alloy.
2. an element that has both metallic and nonmetallic properties, as arsenic, silicon, or boron.
adj.
3. of or pertaining to a metalloid.
4. resembling both a metal and a nonmetal.
[ 1825-35; METALL- + -OID ]