Protuberance \Pro*tu"ber*ance\, n. [Cf. F. protub['e]rance. See Protuberant.]

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.

Syn: 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.

Source: Webster's Revised Unabridged Dictionary (1913)