noun
octonion
A mathematical term for an eight-dimensional hypercomplex number; used in advanced algebra and geometry.
八元数は非結合的な代数系をなす。
Octonions form a non-associative algebraic system.
複素数 (complex number) is two-dimensional and commutative; 八元数 is a further generalization with more dimensions and fewer algebraic properties.
From 八 (eight) + 元 (element) + 数 (number), a direct calque of the English mathematical term 'octonion'.