n. | 1. | Formerly, the metallic base of a fixed alkali, or alkaline earth; - applied by |
a. | 1. | Having the appearance of a metal. |
2. | (Chem.) Having the properties of a nonmetal; nonmetallic; acid; negative. |
Adj. | 1. | metalloid - of or being a nonmetallic element that has some of the properties of metal; "arsenic is a metalloid element" |