Geryon, a king of Erytheia (i.e. red island), on the western borders of the world, with three bodies and three heads, who had a herd of oxen guarded by a giant shepherd and his dog, the two-throated Orthros, which were carried off by Hercules at the behest of his fate.
Definition taken from The Nuttall Encyclopædia, edited by the Reverend James Wood (1907)
Gervinus, Georg Gottfried * Gesenius