1. (a.) Having an empty space or cavity, natural or artificial, within a solid substance; not solid; excavated in the interior; as, a hollow tree; a hollow sphere.

2. (a.) Depressed; concave; gaunt; sunken.

3. (a.) Reverberated from a cavity, or resembling such a sound; deep; muffled; as, a hollow roar.

4. (a.) Not sincere or faithful; false; deceitful; not sound; as, a hollow heart; a hollow friend.

5. (n.) A cavity, natural or artificial; an unfilled space within anything; a hole, a cavern; an excavation; as the hollow of the hand or of a tree.

6. (n.) A low spot surrounded by elevations; a depressed part of a surface; a concavity; a channel.

7. (v. t.) To make hollow, as by digging, cutting, or engraving; to excavate.

8. (adv.) Wholly; completely; utterly; -- chiefly after the verb to beat, and often with all; as, this story beats the other all hollow. See All, adv.

9. (interj.) Hollow.

10. (v. i.) To shout; to holler.

11. (v. t.) To urge or call by shouting.