Waiver means the intentional and voluntary giving up of a known right. It is the intentional and voluntary renunciation, abandonment, or surrender of some claim, right, or privilege.
When the pre-emptor took a leading part in bringing about the transaction by assisting the sellers in selling the land and encouraged the buyers in purchasing it and himself nego¬tiated the price, the conduct of the pre-emptor is sufficient to give rise to waiver and acqui¬escence and as such estoppel operates against him. The State Acquisition and Tenancy Act, 1950 (XXVIII of 1951), Section 96. ….. [Most Rokeya Begum vs. Md. Abu Zaher & ors., 20 BLD (AD) 90]