senile

[ see-nahyl, -nil, sen-ahyl ]

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. Compare peneplain.

noun

1. a senile person.

senile

/ 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

Derived Forms

• senility, noun
• ˈsenilely, adverb

Other Words From

• un·senile adjective

Word History and Origins

Origin of senile¹

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

Word History and Origins

Origin of senile¹

C17: from Latin senīlis, from senex an old man

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

In scathing remarks, Sacks called the president “sleepy and senile” and a puppet manipulated by a deceitful White House staff — which has continuously gaslighted the country by hiding his failing condition.

From Los Angeles Times

“I could put together — and people have — a video of Trump looking absolutely just as senile,” Maher said.

From Salon

Russian state media have consistently mocked the current US president as "senile" and a person not really in control of events.

From BBC

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

From Seattle Times