The description of the word you requested from the astronomical dictionary is given below.
You feel weight when a force acts on the surface of your body. If you stand quietly on the ground, then the ground pushes up against your feet but not against your head, and gravity pulls down all parts of your body equally strongly, so then it feels as if your head and your feet are pushed together, and that gives the feeling of weight.
If you're loose from the ground (for example if you just jumped up), then there is no force pushing against your feet, so then your feet and head are no longer pushed together, and then you feel weightless.
If you sit in an accelerating car, facing forward, then the chair pushes harder against your back, and you feel that as extra weight.
If you sit or stand quietly, then your weight depends on your mass and on the strength of gravity. On the Moon, gravity is less strong than on Earth, so your weight is less on the Moon than on Earth.
Even though weight is a measure for physical force, it is usually described in units of mass, such as the kilogram or pound. A kilogram of weight should be interpreted as "the amount of force of gravity that would act on a mass of one kilogram on Earth". Even on Earth your weight depends on where you are. At the equator you weigh about half a percent (one part in 200) less than at the poles.