Physical object and Solid ground

Physical object noun - A tangible and visible entity; an entity that can cast a shadow.

Solid ground and physical object are semantically related. In some cases you can replace phrase "Solid ground" with "Physical object", this phrases are similar.

Solid ground noun - The solid part of the earth's surface.

Physical object and solid ground are semantically related. Sometimes you can use "Physical object" instead a noun phrase "Solid ground".