What is "omphalomancy"

Omphalomancy \Om"pha*lo*man"cy\, n. [Omphalo- + -mancy.] Divination by means of a child's navel, to learn how many children the mother may have.
--Crabb.

n. divination by means of a child's navel, to learn how many children the mother may have.

Omphalomancy is a method of divination meant to determine how many children a mother may have during her lifetime, based on the belief that the shape of the navel can reveal this information. This is most commonly done with newborn infants, by noting the markings on the newborn's navel.