n. The act of disjoining, or the state of being disjoined; separation; division; distinction.n. Specifically In logic, the relation between the members of a disjunctive proposition or term.n. In logic: a term consisting of two or more terms united by the conjunction or or its equivalent.n. In biology, the separation or alternative inheritance of the parental characters in crosses between inbred varieties or strains of domesticated plants and animals. Called also the law of disjunction, or Mendel's law. See inheritance.