Anthra

Part of speech: noun

Definitions

1. A chemical prefix denoting a compound built on the three-ring aromatic structure of anthracene, derived from Greek for coal
2. Used in chemistry to name substances that contain the fused three-ring hydrocarbon system found in anthracene
3. A combining element in scientific naming that marks a molecule related to anthracene, the coal-tar derived hydrocarbon

Etymology: In ancient Greek, "anthrax" meant coal, especially glowing charcoal. Greek physicians also used it for a carbuncle, a painful boil on the skin. The same name was later given to a deadly disease whose lesions turn dark and blackened, which is why the illness shares a root with the chemistry prefix. That prefix comes from coal tar. Chemists distilling coal tar isolated a substance with three fused benzene rings and named it anthracene, after the Greek for coal. Compounds built on that ring structure, such as anthraquinone, take "anthra-" as a combining form, so the prefix signals the fused-ring skeleton.