Diboride

Part of speech: noun

Definitions

1. A chemical compound whose formula contains two atoms of boron or other bonded anion units, often valued for hardness and heat resistance
2. A binary substance made of two boron atoms combined with a metal or another element, prized in ceramics and cutting materials
3. Any inorganic compound built from two boron atoms paired with a metallic element, used in hard, high-temperature materials

Etymology: "Diboride" is a plain chemical coinage: the prefix "di-", from Greek "dis" meaning "twice" or "two", attached to "boride", the name for a compound of boron with a less electronegative element. In a diboride, two boron atoms are combined with each metal atom, so the formula carries the two-to-one ratio in its name, as "dioxide" does for oxygen. The "di-" prefix is the same one used across chemistry, from "dioxide" and "disulfide" to "dichloride." Chemists adopted this systematic naming in the nineteenth and twentieth centuries to describe ratios of atoms, so the word tells you what the compound contains and how much of it there is.