Definition of "agone"

Three days agone I fell sick.

1611, The Holy Bible, […] (King James Version), London: […] Robert Barker, […], 1 Samuel 30:13

And many a serpent of fell kind, / With wings before, and stings behind, / Subdued; as poets say, long agone, / Bold Sir George, Saint George did the dragon.

1663, Samuel Butler, Hudibras, part 1, canto 2