Dictionary.com
Thesaurus.com
Synonyms

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.


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

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Word Forms

Etymology

Origin of senile

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

Explanation

The word senile describes a person who is experiencing dementia brought about by old age — in other words, someone showing signs of senility. Senile can refer to a loss of physical abilities in old age, but it usually refers to decreased memory and mental faculties. Getting senile is a very serious condition, as an older person might have trouble remembering who their own children are. Many people in nursing homes are senile, because their families aren't able to provide proper care. Of course, people forget things at every age. If you're 10 or 40 and have a bad memory, you're not going senile.

Keep Reading on Vocabulary.com

Vocabulary lists containing senile

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

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

From Seattle Times Apr. 17, 2024

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 Mar. 20, 2024

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

From Salon Jul. 12, 2023

She entered hospice care in late December 2022 with senile degeneration of the brain and was treated with the anxiety drug lorazepam and morphine, a painkiller, according to the report.

From New York Times Feb. 5, 2023

He’s like a hundred years old and completely senile, but he always remembers my name for some reason.

From "Insignificant Events in the Life of a Cactus" by Dusti Bowling

Vocabulary.com logo
by dictionary.com

Join 12,000,000 vocabulary learners

Start learning new words today on VocabTrainer.
You'll remember them forever.

Start training