unum

Unum is the Latin word for "one." It appears in classical and later Western texts and is notably part of the motto E pluribus unum, meaning "Out of many, one," which is used on the Great Seal of the United States and on U.S. currency to symbolize unity arising from diversity. The term also appears in liturgical Latin and in philosophical or theological discussions as a reference to unity.

In computing, unum (plural unums) denotes a family of numeric representations called universal numbers, proposed by John Gustafson and colleagues as an alternative to IEEE 754 floating point. Unums use a variable-length encoding that stores sign, regime, and exponent, plus bits indicating whether the value is exact or an interval. This design can preserve exact endpoints and reduce rounding error, potentially eliminating some conversions. Unums have been explored in research libraries and experimental hardware, but have not become a standard in mainstream computing.

Unum is also the name of an American financial services company, Unum Group, known for life, disability, and other insurance products. Based in Chattanooga, Tennessee, the company operates through multiple subsidiaries, including Colonial Life. It is publicly traded and markets its products to employers and individuals through brokers and partnerships. The Unum brand is used for both corporate and consumer-facing insurance offerings.