Hexachloride

Part of speech: noun

Definitions

1. A chemical compound whose molecules each contain six chlorine atoms bonded to a central element or structure
2. Any substance formed by combining six chlorine atoms with another element or a organic molecular framework
3. A class of chlorinated compounds defined by the presence of six chlorine atoms in each molecule

Etymology: Hexachloride is a plain chemical coinage, built from two pieces that each carry a long history of their own. The first, "hexa-", comes from the Ancient Greek "héx", meaning six, which is the same numeral that sits behind "hexagon" and "hexameter". The second part, "chloride", is much younger than the Greek. It descends from "khlōrós", a Greek adjective meaning pale green or greenish-yellow, which chemists used for the greenish gas they named "chlorine" in the early 1800s. From that gas came the "-ide" ending used for compounds of an element, so "chloride" simply names a compound containing chlorine. Put together, the word describes a compound in which six chlorine atoms are attached to a single molecule or unit. Its meaning rests on the chemistry rather than on any older usage, so there is no shift of sense to trace, only the building blocks themselves. The compound name is an English formation, assembled in the modern scientific style from Greek numerals and the chemical term "chloride".