Atmospheric pressure.. maybe
WEIGHT
Air pressure is the force (weight of Earth's atmosphere) exerted on you by the weight of tiny particles of air, the air molecules above and around you. This is also referred to as "barometric pressure" (measured with a barometer) and will change with altitude or elevation. The standard pressure is 1 ATM (atmosphere), equal to 101325 pascals or 1013.25 mbar.
its is just called Force= F
No weight is a measurement of how much force something experiences due to gravity.
It is your weight, which manifests as a downward force exerted by your body, although it is also an acceleration to a greater force if you fall.
Atmospheric pressure
Downforce
Downforce
The atmospheric pressure at that place and at that time.
Yes, pressure increases with depth as a result of the weight of water above a given depth. Weight is caused/determined by gravity.
WEIGHT
The measurement will be in terms of force or weight just as the measurement of the force holding a person to the earth is given by their weight.
You cannot. You do not have the necessary information.
The amount of force is called stress.
The Amount Of Force
What do you mean "... based on"? The athmosperic pressure is "weight of air" and it can be measured. Strikly speaking: "force per unit area exerted against a surface by the weight of air above that surface at any given point" (wikipedia) Ap could be given in force/area units for example lb/sq ft, kg/sq meter etc.
If you know the force of gravity then mass = weight/gravitational force. If you don't then you cannot. Knowing the volume is useless.