1. showing a decline in mental ability because of old age
Usage: often considered offensive when referring to people
2. relating to or characteristic of old age
Usage: medical or technical use

Examples

• The doctor explained that senile dementia affects memory and thinking.
• Many people worry about becoming senile as they age.
• The term ‘senile’ is now considered outdated in medical practice.
• Senile changes in the brain can affect cognitive function.
• She preferred to say her grandfather was forgetful rather than senile.
• The nursing home specializes in caring for patients with senile conditions.