羟自由基 qiǎngzìyóujī hydroxyl radical Definitions Defs Origin Strokes Stroke Words Sentences Sents 羟 羥 qiǎng hydroxyl hydroxyl radical; an atom group consisting of one hydrogen atom and one oxygen atom自由基 zìyóujī free radical (chemistry) an atom or group of atoms that has at least one unpaired electron and is therefore very reactive