What is the meaning of Hollow?

A small valley between mountains.

A sunken area on a surface.

An unfilled space in something solid; a cavity, natural or artificial.

A feeling of emptiness.

to make a hole in something; to excavate

Having an empty space or cavity inside.

Distant, eerie; echoing, reverberating, as if in a hollow space; dull, muffled; often low-pitched.

Without substance; having no real or significant worth; meaningless.

Insincere, devoid of validity; specious.

Concave; gaunt; sunken.

Pertaining to hollow body position

Synonym of empty (lacking between the onset of tasting and the finish)

Completely, as part of the phrase beat hollow or beat all hollow.

To call or urge by shouting; to hollo.

Alternative form of hollo

Source: wiktionary.org