Definition:Weight (Physics)
Definition
The weight of a body is the force exerted on it by the influence of a gravitational field.
The context is that the gravitational field in question is usually that of the Earth.
There is a certain amount of confusion in the common mind between weight and mass. The latter is usually determined by measuring its weight. But while the mass of a body is (under normal circumstances) constant, its weight varies according to its position relative to the gravitational field it is in. However, the fact that under usual terrestrial conditions the gravitational field is more or less constant (any differences being detectable only by instruments) means that the weight and mass of an object are commonly considered "the same".
Dimension of Weight
The dimension of weight is $M L T^{-2}$: mass times acceleration, i.e. a force.