adj.
- Of, relating to, or characteristic of old age.
- Relating to or exhibiting memory loss or mental impairment associated with aging.
- Geology. Worn away nearly to the base level, as at the end of an erosion cycle.
[Latin senīlis, from senex, sen-, old.]
senilely se'nile'ly adv.WORD HISTORY In earlier writings one finds phrases such as "a senile maturity of judgment" and "green and vigorous senility," demonstrating that senile and senility have not always been burdened with their current negative connotations. These two words are examples of pejoration, the process by which a word's meaning changes for the worse over time. Even though senile (first recorded in 1661) and senility (first recorded in 1778) initially had neutral senses such as "pertaining to old age" (the sense of their Latin source, the adjective senīlis), it is probable that the mental decline that sometimes accompanies old age eventually caused negative senses to predominate. Although recent medical research has demonstrated that the memory and cognitive disorders once designated by senility are often caused by various diseases rather than the aging process itself, it seems unlikely that the word will regain its neutral senses.
See crossword solutions for the clue 
