Protuberance

Part of speech: noun (n.)

That which is protuberant swelled or pushed beyond the surrounding or adjacent surface; a swelling or tumor on the body; a prominence; a bunch or knob; an elevation. Solar protuberances (Astron.), certain rose-colored masses on the limb of the sun which are seen to extend beyond the edge of the moon at the time of a solar eclipse. They may be discovered with the spectroscope on any clear day. Called also solar prominences. See Illust. in Append.

Synonyms: Projection, Protuberance. 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.