\Se"nile\, a. [L. senilis, from senex, gen. senis, old,
an old man: cf. F. s['e]nile. 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.
{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.