What does "senile" mean?

Senile: Of or pertaining to old age; proceeding from, or characteristic of, old age; affected with the infirmities of old age; as, senile weakness. "Senile maturity of judgment." Boyle. Senile gangrene (Med.), a form of gangrene occuring particularly in old people, and caused usually by insufficient blood supply due to degeneration of the walls of the smaller arteries.