Gerontologist (noun)

1. A specialist in gerontology.
2. A scientist who studies the biological, psychological, and social aspects of aging.

Origin:

From greek geron, geront- meaning "old man" + -logist meaning "study of".

Examples:

1. She is a gerontologist and studies the aging process.
2. He is a gerontologist and specializes in elder care.
3. The gerontologist gave a talk on age-related diseases.
4. She became a gerontologist after her grandfather's death.
5. Gerontologists are concerned with the well-being of older adults.