[{"Bold_text": "noun", "List Items": ["a unit of absorbed dose absorbed doseof radiation equal to 0.01 gray : not a standard SI unit, the rad is still used, especially in the U.S., but it is increasingly disfavored."]}, {"Bold_text": "noun", "List Items": ["Informal.a radical, especially a person with extreme views on political and social issues."]}, {"Bold_text": "adjective", "List Items": ["Slang.excellent; wonderful; cool:a high speed, high energy, totally rad racing game."]}, {"Bold_text": "abbreviation for", "List Items": ["radian ; radians."]}, {"Bold_text": "abbreviation for", "List Items": ["radical.", "radix."]}]