Dotard

Dotard: a person in his or her dotage

Dotage:the period of old age : the time when a person is old and often less able to remember or do things

Ex. The gentleman next door had been vilified by Nicholas; rudely stigmatised as a dotard and an idiot; and for these attacks upon his understanding, Mrs Nickleby was, in some sort, accountable.

(خَرِف)الكبير فى السن اللذى وصل الى حد التخريف