Weight is indeed a force, and according to Newton's Second Law, the net force on an object is zero when it is not accelerating. So, how can we say a person has weight even when not accelerating?
The confusion here arises from a slight difference in the usage of the term "weight" in everyday language and in the context of physics. In physics, weight is the force exerted on an object due to gravity. It is defined as the product of the mass of the object and the acceleration due to gravity (W = mg), where g represents the acceleration due to gravity.
When we say a person has weight, we are referring to the force that gravity exerts on their mass. This force is always present, regardless of whether the person is accelerating or not. However, when a person is not accelerating (e.g., when standing still on the ground), the net force acting on them is indeed zero, as the gravitational force is balanced by the normal force exerted by the ground.
In other words, weight is the force of gravity acting on an object, and it always exists as long as the object has mass. The absence of acceleration simply means that the net force on the object is zero, not that the force of gravity (weight) is zero.