Giddonah was the high priest in the land of Gideon when Korihor, the anti-Christ, came there to preach around 74 B.C. After Korihor was taken, bound, and brought before him and the chief judge over the land, Giddonah questioned him: why he went about perverting the ways of the Lord, taught the people that there would be no Christ, and spoke against the prophecies of the holy prophets (Alma 30:21-22).
Korihor answered that he refused to teach what he called the foolish traditions of their fathers, denied that the people were in bondage, and said no one could know that Christ would come. When Giddonah and the chief judge saw that his heart was hardened and that he reviled against God, they made no reply but had him bound and sent to the land of Zarahemla, to be brought before Alma and the chief judge who was governor over all the land, Nephihah (Alma 30:28-29).