The mother. A person's mother. The elder wise woman of the family. The Grand mother would be "grand old Earth" for instance.
In the 5% Nation of Islam, the family is identified with the planets of the universe. The Man is the Sun. The child is the Star. The wife or woman is the Earth (Her mind is the MOON). So a person's wife would be his Earth and his mother would be his "old Earth".
"My OLD EARTH is going to watch our seeds when we go our business trip".