abelian

adjective2

1. •
   Of an algebraic structure (usually a group or algebra), having a commutative defining operation.

   • The interesting aspect here is that U₃ is irreducible, even though all irreps over the complexes are one-dimensional because ℤ₄ is abelian. — 1996
2. •
   Of a binary function, commutative.

noun1

1. •
   (historical) A member of a sect in fourth-century Africa mentioned by St. Augustine, who states that they married but lived in continence after the manner, as they claimed, of Abel.

   • The Abelians were only a moderate sort of Encratites and Novatians, who absolutely condemned matrimony, while the Abelians approved of and retained it. — 1826