Wiktionary
hypercomplex number
n. (context mathematics English) A complex number consisting of more than two square roots of negative one, creating multiple simulated dimensions.
Wikipedia
Hypercomplex number
In mathematics, a hypercomplex number is a traditional term for an element of a unital algebra over the field of real numbers. The study of hypercomplex numbers in the late 19th century forms the basis of modern group representation theory.
Usage examples of "hypercomplex number".
What word leaps to mind when I say that one hyper-complex number times a second hypercomplex number is always equal to the second such number times the first?