senile

American  

[see-nahyl, -nil, sen-ahyl] / ˈsi naɪl, -nɪl, ˈsɛn aɪl /

adjective

1. showing a decline or deterioration of physical strength or mental functioning, especially 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.

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noun

1. a senile person.

senile British  

/ ˈsiːnaɪl, sɪˈnɪlɪtɪ /

adjective

1. of, relating to, or characteristic of old age

2. mentally or physically weak or infirm on account of old age

3. (of land forms or rivers) at an advanced stage in the cycle of erosion See old

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Other Word Forms

• senilely adverb
• senility noun
• unsenile adjective

Etymology

Origin of senile

First recorded in 1655–65; from Latin senīlis “old,” from sen(ex) “old man” ( senior ) + -īlis -ile

Example Sentences

I asked him about that moment just after it happened, and had asked him whether the president was senile the day before.

From BBC

Especially if a person seems to go senile very quickly, check their vitamin B12!

From Seattle Times

She has no choice but to carry this pregnancy to term, surrounded by jealous novitiates, senile nuns, controlling male leadership and a secret sect of the sisterhood who wear crimson shrouds over their faces.

From Los Angeles Times

One who approves of his performance nevertheless called him “senile.”

From Seattle Times

There have always been eccentric, senile and downright simple-minded members of Congress.

From Salon