%senile%

a. [ L. senilis, from senex, gen. senis, old, an old man: cf. F. sénile. See Senior. ] 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. [ 1913 Webster ]

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. [ 1913 Webster ]