Definition:Pairwise Disjoint

Definition
A family of sets $\left \langle {S_i} \right \rangle_{i \in I}$ is said to be pairwise disjoint iff:
 * $\forall i, j \in I: i \ne j \implies S_i \cap S_j = \varnothing$

Here, $\cap$ denotes intersection, and $\varnothing$ denotes the empty set.

Alternatively, we can say that the sets $S_i$, where $i \in I$, are pairwise disjoint.

Also known as
Other names for pairwise disjoint include mutually disjoint and nonintersecting.

Also see

 * Disjoint Sets