se·nile (sēnīl′, sĕnīl′)
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.]
se·nili·ty (sĭ-nĭlĭ-tē) n.
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Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
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