education or instruction in the fundamentals of a field of knowledge
"he lacks the foundation necessary for advanced study"
"a good grounding in mathematics"
Fundamental knowledge or background in a field or discipline.
"Her years of research gave her a solid grounding in quantum mechanics that allowed her to lead the team effectively."
present participle of ground
"The storm left everyone without electricity, so we had to wait for the power lines to be grounded before it was safe to use our appliances again."