Sets A and B are disjoint if they have no elements in common; that is, if A ∩ B = Ø.
Computer
A term applied to two sets that have no element in common, i.e. such that the intersection of the sets results in the empty set. A number of sets are said to be mutually disjoint if each pair is disjoint.
Philosophy
Two sets are disjoint if they have no member in common.