|1.||of, relating to, or characteristic of old age|
|2.||mentally or physically weak or infirm on account of old age|
|3.||See old (of land forms or rivers) at an advanced stage in the cycle of erosion|
|[C17: from Latin senīlis, from senex an old man]|
|a chattering or flighty, light-headed person.|
|a fool or simpleton; ninny.|
senility se·nil·i·ty (sĭ-nĭl'ĭ-tē)
The state of being senile.
The mental and physical deterioration characteristic of old age.