adj. 1. a. Relating to or having diminished cognitive function, as when memory is impaired, because of old age. b. Being a disease or condition whose cause is primarily advanced age: senile cataracts. 2. Geology At the end of an erosion cycle: senile soil. [Latin senīlis, proper to or characteristic of old people, aged, from senex, sen-, old; see sen- in the Appendix of Indo-European roots.] senile′ly adv. se·nili·ty (sĭ-nĭlĭ-tē) n. |
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