Found 2 items, similar to radon.
English → English (WordNet) Definition: radon radon n : 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 [syn: Rn, atomic number 86 ]
English → English (gcide) Definition: radon Noble \No"ble\, a. [Compar. Nobler; superl. Noblest.] [F. noble, fr. L. nobilis that can be or is known, well known, famous, highborn, noble, fr. noscere to know. See know.] 1. Possessing eminence, elevation, dignity, etc.; above whatever is low, mean, degrading, or dishonorable; magnanimous; as, a noble nature or action; a noble heart. [1913 Webster] Statues, with winding ivy crowned, belong To nobler poets for a nobler song. --Dryden. [1913 Webster] 2. Grand; stately; magnificent; splendid; as, a noble edifice. [1913 Webster] 3. Of exalted rank; of or pertaining to the nobility; distinguished from the masses by birth, station, or title; highborn; as, noble blood; a noble personage. [1913 Webster] Note: Noble is used in the formation of self-explaining compounds; as, noble-born, noble-hearted, noble-minded. [1913 Webster] Noble gas (Chem.), a gaseous element belonging to group VIII of the periodic table of elements, not combining with other elements under normal reaction conditions; specifically, helium, neon, argon, krypton, xenon, or radon; also called inert gas. Noble metals (Chem.), silver, gold, and platinum; -- so called from their resistance to oxidation by air and to dissolution by acids. Copper, mercury, aluminium, palladium, rhodium, iridium, and osmium are sometimes included. [1913 Webster] Syn: Honorable; worthy; dignified; elevated; exalted; superior; sublime; great; eminent; illustrious; renowned; stately; splendid; magnificent; grand; magnanimous; generous; liberal; free. [1913 Webster]