No, in math and physics, it means that it's a quantity too low to be considered significant. If there was no gravity, then the solar systems wouldn't exist. Planets would simply drift through space as frozen rocks. We call it Zero-G because it's an archaic term from early spaceflight. It's not observable to us, as our mass is too low to be influenced. So before we could concretely measure it, we figured can't feel=isn't there.