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

He concluded, “Now you’re just senile and tone-deaf.”

From Salon

“By the way, when Joe Biden rambled like this, all of us were like, ‘This man is obviously senile,’" Kosta said. "But now that he’s dropped out, it’s becoming more obvious that Trump’s brain isn’t exactly in great shape, either.

From Salon

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

From BBC

Republicans had spent months, they said, caricaturing the president as senile and checked out, and therefore all Biden had to do was show up and clear the low bar of seeming to be in full possession of his faculties.

From Slate

“Biden is getting old, but I’d rather work with old, senile than a crazy man,” Donelson shot back.

From Los Angeles Times