senile: Meaning and Definition of

se•nile

1. showing a decline or deterioration of physical strength or mental functioning, esp. short-term memory and alertness, as a result of old age or disease.
2. of or belonging to old age or aged persons; gerontological; geriatric.
3. (of topographical features) having been reduced by erosion to a featureless plain that stands everywhere at base level. Cf.

1. a senile person.