[{"Bold_text": "noun", "List Items": ["a grayish-white element having a metallic luster, vaporizing when heated, and forming poisonous compounds.:As;:74.92;:33.", "arsenic trioxide arsenic trioxide.", "a mineral, the native element, occurring in white or gray masses."]}, {"Bold_text": "adjective", "List Items": ["of or containing arsenic, especially in the pentavalent state."]}]