free radical
Chemistry term for an atom or molecule with an unpaired electron, often highly reactive.
遊離基は体内で細胞を傷つけることがある。
Free radicals can damage cells in the body.
free radical reaction
Compound of 遊離 (yūri, 'free, detached') and 基 (ki, 'radical, group'), a calque of English 'free radical'.