Gerontius Took, also known as the Old Took, is the name of Bilbo's maternal grandfather in The Hobbit. He lived to the age of 130, which is unusually long for a hobbit.
This is indeed, in origin, a Greek name.Gerontius is the latinized form of Gerontios (Γερόντιος), which is derived from γέρων (geron) meaning "old man, dignified elder." Also compare Greek words like γερόντιον (gerontion) "little old man" and the verb γεροντιάω (gerontiaō) "to grow old". Even compare the modern English words 'gerontic' and 'gerontology', which derive from the same Greek root.As such, Gerontius should also be categorised as Late Greek (Latinized), next to Late Roman (as the name was indeed borne by Romans as well).