hollow

Remove the inner part or the core of.

Remove the interior of.

“hollow out a tree trunk”

A small valley between mountains.

“he built himself a cabin in a hollow high up in the Appalachians”

A depression hollowed out of solid matter.

A cavity or space in something.

“hunger had caused the hollows in their cheeks”

Devoid of significance or force.

“a hollow victory”

As if echoing in a hollow space.

“the hollow sound of footsteps in the empty ballroom”

Lacking in substance or character.

“a hollow person”

Not solid; having a space or gap or cavity.

“a hollow wall”

“a hollow tree”