Onomancy is a form of divination which uses the letters in someone's given name. There are a number of ways in which a name can be analyzed in this system of divination, and many cultures have some form of onomancy. The practice of reading hidden meanings into words and phrases is also sometimes applied to texts like the Torah by people who believe that secret messages were embedded into the language of these texts.
Numerous instances of onomancy can be found in classical writings. The Greeks and Romans, for example, both attached great importance to the symbolism of given names, and expecting parents would often consult a fortunetelling authority to get feedback on their potential choices of name. Some names were viewed as inauspicious for a variety of reasons, with fortunetellers considering issues like the date and time of birth, the location of birth, and the names of the parents in their evaluation of prospective names.
In the Middle Ages, onomancy was very popular in many parts of Europe. Fortunetellers would use someone's name to map out his or her fate and future, looking at things like the number of vowels in a name, or the meanings unveiled when the letters were converted to numerical values. The number of letters was also viewed as important, and some people clearly devised very complex codes for evaluating names with the hopes of attracting customers.
Onomancy was not restricted to Europe. It was also very popular in Asia, and continues to be so today. In China, for example, the number of strokes used to write your name is believed to be important, as are the characters used to write your name. Parents try to pick auspicious names for their children so that they will grow up wealthy, happy, or powerful, and parents who choose poorly will sometimes be criticized for setting their children up to fail.
This form of divination continues to be practiced in some regions of the world today, although people are not always serious about it. Many people in the West like to play with converting their names to numerical values and looking up the symbolic meaning of those numbers, and some people even change their names in an attempt to create a more pleasing numerical value.
These is some dispute over the spelling of “onomancy.” In Greek, onos means “donkey,” and some people have suggested that “onomancy” really means “divination by donkey.” The Greek term for name is onoma, so “onomancy” could more properly be “onomamancy” or “onomatomancy.” However, “onomancy” has come to be the commonly accepted and used spelling in most dictionaries.