Onomancy (or nomancy) is divination based on a subject's name.
Onomancy gained popularity in Europe during the Late Middle Ages, but is said to have originated with the Pythagoreans in antiquity.
[1] Several methods of analyzing a name are possible, some of which are based on arithmancy or gematria.
The system given there involves adding up the numerical values of the letters in the names of two antagonists, dividing the total for each person by 9, and comparing the remainders with a table which predicts the victor.
[2][a] In China, Taiwan, and Japan, onomancy is known as 姓名判断 (Chinese: xingming panduan; Japanese: seimei handan).