Meaning: father of abundance, or my father excels.
He was the 10th high priest, and the 4th in descent from Eli. When his father was slain with the priests of Nob, he escaped, and bearing with him the ephod, he joined David, who was then in the cave of Adullam (1 Samuel 22:20-23; 23:6).
He remained with David, and became priest of the party of which he was the leader (1 Samuel 30:7). When David ascended the throne of Judah, Abiathar was appointed high priest (1 Chronicles 15:11; 1 Kings 2:26) and the “king’s companion” (1 Chronicles 27:34).
Abiathar was deposed (the only historical instance of the removal of a high priest) and banished to his home at Anathoth by Solomon, because he took part in the attempt to raise Adonijah to the throne. The priesthood thus passed from the house of Ithamar (1 Samuel 2:30-36; 1 Kings 1:19; 2:26-27). Zadok now became sole high priest.
In Mark 2:26, reference is made to an occurrence in “the days of Abiathar the high priest.” But from 1 Samuel 22, we learn that this event took place when Ahimelech, the father of Abiathar, was high priest. The apparent discrepancy is satisfactorily explained by interpreting the words in Mark as referring to the lifetime of Abiathar, and not to his term of office. It is not implied in Mark that he was actually high priest at the time referred to. Others, however, think that the loaves belonged to Abiathar, who was at that time (Leviticus 24:9) a priest, and that he either himself gave them to David, or persuaded his father to give them.