noun, noun or participle which takes 'suru', intransitive verb
Refers to mental and physical decline due to old age. Often used with する to mean 'become senile'. The kanji 耄碌 are somewhat rare and may be replaced by kana in modern writing.
祖父は最近耄碌して、家族の名前を忘れることがある。
My grandfather has become senile recently and sometimes forgets family members' names.
Caring for a senile old person is tough.