Here are some examples of words with this root:
* Gerontology: The study of aging and the elderly.
* Geriatrics: The branch of medicine concerned with the health and care of elderly people.
* Gerontophobia: Fear of old people.
* Gerontocracy: Rule by old people.
Keep in mind that while "ger-" is a common Greek root for "old," it's not the only one. Other roots like "sen-" (from "senex" meaning "old man" in Latin) can also convey the same meaning.