- a highly radioactive metallic element whose decay yields radon gas and alpha rays. Symbol: Ra; atomic weight: 226; atomic number: 88.
- a lustrous rayon or silk fabric constructed in plain weave and used in women's apparel, lining, and drapery.
- a highly radioactive luminescent white element of the alkaline earth group of metals. It occurs in pitchblende, carnotite, and other uranium ores, and is used in radiotherapy and in luminous paints. Symbol: Ra; atomic no: 88; half-life of most stable isotope, 226 Ra: 1620 years; valency: 2; relative density: 5; melting pt: 700°C; boiling pt: 1140°C
- (as modifier)
