Read Edit View history 氡 dōng radon Origin Definitions Defs Strokes Stroke Words Sentences Sents created sense approved 氡 · dōng · radon 2026/03/04 氡 dōng radon radon (chemistry) 氡是一种具有放射性的惰性气体。 noun created sense Mar 4, 2026, 02:25 AM