Advantages of adopting the operational definition of weight
  With rare exceptions, in high school and college/university physics courses literature and in journals of physics, the weight is defined as a gravitational force or an exclusive consequence of it. These definitions lack logic from the perspective of present knowledge and can be misleading. The operational definition of weight of a body as the force the body exerts on its support or suspender can eliminate the ambiguities associated to "true weight", "apparent weight", "state of weightlessness", "zero weight", "zero gravity", "microgravity", "vertical", "up" and "down". Nevertheless, the concept of weight of a body is not fundamental in Physics and its exclusion from the physics vocabulary will eliminate some of former concepts or their ambiguousness with evident benefit for physics teaching and learning. This paper discusses weight of a body concepts and presents several examples that show the advantages of avoiding its use or adopting the above-mentioned operational definition. It is believed that this will eliminates the frequent identification with the body's mass and will boost student's understanding associated subjects. 
J.M.L. Figueiredo