free radical
noun [ C often plural ] chemistry specialized uk/ˌfriː ˈræd.ɪ.kəl/ us/ˌfriː ˈræd.ɪ.kəl/
自由基，游离基
a molecule that has an extra electron and therefore reacts very easily with other molecules
Free radicals have been implicated in cancer and many other serious diseases. 游离基是罹患癌症和许多其他严重疾病的潜在原因之一。