| a combining form meaning “old age,” used in the formation of compound words: gerontology. |

| geronto- or geront- pref. Old age; aged one: gerontology. [French géronto-, from Greek geronta-, from gerōn, geront-, old man; see gerə-1 in Indo-European roots.] |
geronto- or geront-
pref.
Old age: gerontology.