Cores are used to create hollow areas in the mold that would otherwise be impossible to achieve.

A little bit behind the lower teeth is a hollow area (or pit) in the lower surface of the mouth.

Workers trying to retrieve it found a hollow area into which cleaning people over many years had swept debris.

The avon has a somewhat large and oval-shaped hollow area near the tip.

The removal of the gas ring had left a round hollow area at the base of the tank.

The hollow area isn't very big at all.

That is, a piece of plastic formed into nearly the shape intended, with a hollow area in the middle.

A little ways back from the lower teeth is a hollow area (or pit) in the lower surface of the mouth.

She hoisted him higher and moved off to the side of the gates, to a hollow area already dark with shadows.

It can also mean a hollow area within the body.