[see-nahyl, -nil, sen-ahyl] 
| 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. | Physical Geography. (of topographical features) having been reduced by erosion to a featureless plain that stands everywhere at base level. Compare peneplain. |
| 4. | a senile person. |
| se·nile (sē'nīl', sěn'īl') adj.
[Latin senīlis, from senex, sen-, old; see sen- in Indo-European roots.] 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. |
senile se·nile (sē'nīl', sěn'īl')
adj.
Relating to, characteristic of, or resulting from old age.
Exhibiting the symptoms of senility, as impaired memory or the inability to perform certain mental tasks.
naɪl