The other common biblical word for God is Elohim . In fact, the rabbis interpret Elohim to represent God's attribute of justice, whereas Adonai represents God's attribute of mercy. Elohim is the basic form of Eloheinu , our God, which we use often in liturgy. Another biblical name for God is El Shaddai . As this week's Torah portion makes clear, it is the name by which Abraham knew God.
Some scholars suggest that it is related to the Hebrew word shad , meaning breast.
It is clear that the ancient Hebrews had many names for God, and just as clear that they were quite careful about using them. In fact, they often went to great lengths to avoid using them directly, whether orally or in writing. The answer has to do with the power of the name, especially the spoken name in the ancient world. To name someone was to enter into a personal relationship. Thus, the revelation of a divine name and its continued use were substantially important to a people as a religious community.