What are Magi?
The word "magi" means wise men. The term is used to refer to the three wise men who came from the east to worship the newborn Jesus in some of the Gospels.
The word is used in the title sort of as irony and also to refer to the idea that Jim and Della are actually wise.
The word is ironic because the wise men had really splendid gifts to give Jesus -- gold, frankincense and myrrh. They were clearly rich. But Jim and Della don't have hardly anything to give one another.
The word also refers to Jim and Della being wise for being so in love and appreciating each other so much.
The Magi were the three wise men who brought gifts to the infant Jesus. They saw the light in the sky and followed the star to the stables. They were also the ones who told Joseph to travel with his family somewhere else so that they would not be caught.
The Magi are based on the Christian beliefs and told about in the bible. The author used them to represent the idea of the gifts that have been given freely by Della and Jim. They both made a big sacrifice for one another expecting nothing in return.
Christians the world over exchange gifts at Christmas time in honor of the night that Christ was born.