adjective: (mathematics) Of an algebraic structure, having a commutative defining operation.
adjective: (mathematics) Of a binary function, commutative.
noun: (Roman Catholicism, 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.
adjective: (mathematics, group theory, dated) Alternative letter-case form of abelian [(mathematics) Of an algebraic structure, having a commutative defining operation.]