cutpoint

Noun

 * 1)  A point of a connected space whose removal causes the resulting space to be disconnected.
 * Every point of a line is a cutpoint, but no point of a circle is a cutpoint.
 * 1)  A cutoff point (cutoff value, threshold value), that is, a cutoff: the amount set by an operational definition as the transition point between states in a discretization or dichotomization.