痴呆 (chī dāi): Глупые

After Grandpa turned eighty, he gradually showed symptoms of dementia, often forgetting that he had just eaten and even failing to recognize family members.

That old man has Alzheimer's disease and often gets lost when he goes out, so his daughter sewed a contact card into his clothes.

The doctor diagnosed him with early-onset dementia and suggested that family members chat with him more to slow the worsening of the condition.

As his condition worsened, his dementia became increasingly severe; even the simplest tasks like dressing and eating required help from others.