Lacking value, use, or substance
A space in an otherwise solid mass
An area sunk below its surroundings
Sounding as though from a cave
beat all hollow
The blue-bird makes her nest in a hollow tree and her eggs are blue.
The skull looked up through hollow eyes, just as the flashlight died, plunging the pair into a blackened void of darkness.
The dirt hit his body with a hollow thud.
In this way two cavalry regiments galloped through the Semenovsk hollow and as soon as they reached the top of the incline turned round and galloped full speed back again.
So high as heaved the tumid hills, so low Down sunk a hollow bottom broad and deep, Capacious bed of waters.