# senile

/ˈsiˌnaɪɫ/ (US) · /sˈiːnaɪl/ (UK) · CEFR C1 · Adjective

Source: https://englishreference.com/word/senile
Updated: 2026-05-18

## Definition

having or showing the mental abilities of an old person. It is often used to describe someone who has trouble remembering things or thinking clearly because of old age.

For teachers: characterised by or suffering from the mental deterioration associated with old age. Often carries a derogatory or clinical tone when used to describe a person's cognitive state.

## Examples

- He is quite senile and often forgets where he puts his keys.
- The doctor explained that some degree of senility is normal as people age, but sudden memory loss requires further testing.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.