assession noun3 •A sitting beside or near; especially as a participant in an official proceeding such as a meeting of an organization or a court case; an official membership or seat.A significant point has been the quiet and un-eventful assession of Belarus to the Non-Proliferation Treaty ( NPT), and the implementation of regular international nuclear safeguards inspections. — 1996 •The act of assessment.The design criteria are evaluated on the basis of stress assession, which are the nature constraint conditions for optimum design . — 1981 •(historical) An official review and recognition of the feudal distribution of land, including the tenants living on that land and the terms of their holdings, which was held every seven years (the term of each tenant's lease). formsassessions