Word Origin & History
agate
1570, from M.Fr. agathe, from O.Fr. acate, from L. achates, from Gk. achates, the name of a river in Sicily where the stones were found. But the river could as easily be named for the stone. The earlier Eng. form of the word, achate (1230), was directly from Latin. Figurative sense of "a diminutive person" (1597) is from the now-obsolete meaning "small figures cut in agates for seals," preserved in typographer's agate (1838), the U.S. name of the 5.5-point font called in Great Britain ruby. Meaning "toy marble made of glass resembling agate" is from 1843 (colloquially called an aggie).