waiver - the intentional or voluntary relinquishment of a known right, or such conduct as warrants an interference of the relinquishment of such right, or when one dispenses with the performance of something he is entitled to exact, or when one is in possession of any right ... with full knowledge of the material facts, does or forbears to do something the doing of which or the failure of forbearance to do which is inconsistent with the right , or his intention to rely upon it