獃 dāi HSK5 dull Origin Definitions Defs Strokes Stroke Words Sentences Sents 老年痴呆症 lǎoniánchīdāizhèng Alzheimer's senile dementia or Alzheimer's disease老年性痴呆症 lǎoniánxìngchīdāizhèng senile dementia 老年痴呆 lǎoniánchīdāi dementia senile dementia or Alzheimer's disease