Would you accept the magazine Physics World as knowing what a kilogram is? See this article for the following statement:
Scientists have proposed two ways to redefine the unit of mass. The first is based on the Planck constant and requires a 1-kilogram mass to be supported against Earth’s gravity using a precisely measured magnetic force.
See, a kilogram is a unit of mass, and when it has a gravitational acceleration applied to it, you get a force. That whole F=ma thing.
A kilogram is a unit of mass. It exerts a force (weight), because of gravitational attraction between masses (the earth and the kg of mass), but the force will change based upon the gravitational attraction between the two.
That may be one way for defining mass. I prefer using a different physcial constant - Avagadro's number. This proposale is to use isotopically pure silicon to form a sphere with an exactly known quantity of atoms. That avoids having to use a material suceptible to magnetic fields and to gravity, both of which would have to be calibrated and standardized. Earth's mass changes and it's gravity field is not purely homogeneous, plus all the corrections for celestial motion based on location. An ideal standard should minimize all other interactions as much as possible. But don't explain any of that to Nathan Zachary. He simply doesnt understand the dimensions of units and their physical meanings.