radio-carbon/ˌredɪəu ˈkɑ:bən; ˌredɪo`kɑrbən/ n[U]radioactive form of carbon present in organic materials, used in carbon dating 放射性碳（有机材料中碳元素的放射性形式, 用以测定某物的年代）.
牛津英汉双解词典