Senility (noun)

The state or condition of being senile, characterized by the decline of mental and physical abilities in old age.

Origin:

From latin senilitas, from senex ("old"), from sen- ("old") + -ilitas ("state, condition").

Examples:

1. The novel depicts the main character's descent into senility.
2. He was diagnosed with senility and could not remember his own name.
3. The symptoms of senility include memory loss and confusion.
4. The elderly woman's senility made her unable to live on her own.
5. He was in the early stages of senility and was forgetful but still able to function on his own.