senectuous
/ˌsɛnɛkˈtʃuːəs/; /ˌsɛnˈɛktʃuːəs/Definitions
1. adjective
Describing something as being related to, or characteristic of, old age; especially, relating to the state of being old or elderly.
“The senectuous air in the attic made her feel nostalgic.”
2. noun
A state of being old or elderly, especially one characterized by declining physical or mental abilities.
“The doctor studied the patient’s senectuous symptoms to determine the best course of treatment.”