PROTU'BERANCE, noun [Latin protuberans, protubero; pro and tuber, a puff, bunch or knob.] A swelling or tumor on the body; a prominence; a bunch or knob; any thing swelled or pushed beyond the surrounding or adjacent surface; on the surface on the earth, a hill, knoll or other elevation.

Protuberance differs from projection, being applied to parts that rise from the surface with a gradual ascent or small angle; whereas a projection may be at a right angle with the surface.