Ground level and Ground-floor

Ground level noun - The height of the ground on which something stands.

Ground-floor and ground level are semantically related. In some cases you can replace phrase "Ground-floor" with "Ground level", this phrases are similar.

Ground-floor adjective - On the floor closest to level with the ground.

Ground level and ground-floor are semantically related. You can use "Ground level" instead a noun phrase "Ground-floor".