English noun: radon | |||
1. | radon (substance) a radioactive gaseous element formed by the disintegration of radium; the heaviest of the inert gasses; occurs naturally (especially in areas over granite) and is considered a hazard to health | ||
Synonyms | atomic number 86, Rn | ||
Broader (hypernym) | argonon, chemical element, element, inert gas, noble gas | ||