Definition:Connectivity

Definition
Let $G$ be a graph.

Then $\kappa \left({G}\right)$, the connectivity of $G$, is the smallest $k \in \Z_{>0}$ such that $G$ is $k$-connected.

If $G$ is disconnected, or if $G$ has fewer than 2 vertices, then $\kappa \left({G}\right) = 0$.