thoriaPronunciation: /ˈθɔːrɪə/Definition of thoria noun [mass noun] Chemistry thorium dioxide, a white refractory solid used in making gas mantles and other materials for high-temperature applications. Chemical formula: ThO2 Origin: mid 19th century: from thorium, on the pattern of words such as alumina and magnesiathoria in other Oxford dictionaries Definition of thoria in the US English dictionary
