RADON
radon, Rn, atomic number
(noun) 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
Source: WordNet® 3.1
Etymology
Contraction of radium emanation, since the element appears in the radioactive decay of radium.
Noun
radon (uncountable)
The chemical element (symbol Rn, formerly Ro) with atomic number 86. It is an odorless, colorless, chemically inert but radioactive noble gas.
The most stable isotope of this element, 22286Rn.
Synonyms
• emanation (obsolete) (definition 1)
• exradio (archaic) (definition 2)
• niton (obsolete) (definition 1)
Anagrams
• Ardon, Daron, Doran, Drona, NORAD, Nador, Nardo, Ronda, adorn, and/or, andro, andro-, norad, rando
Source: Wiktionary