Anomaly

1. n. Any deviation from the essential characteristics of a specific type.
2. n. Deviation from the common rule; an irregularity; anything anomalous.
3. n. The angular distance of a planet from its perihelion, as seen from the sun. This is the true anomaly. The eccentric anomaly is a corresponding angle at the center of the elliptic orbit of the planet. The mean anomaly is what the anomaly would be if the planet’s angular motion were uniform.
4. n. The angle measuring apparent irregularities in the motion of a planet.

The word meanings were obtained from OPTED(The Online Plain Text English Dictionary), which is based on “The Project Gutenberg Etext of Webster’s Unabridged Dictionary” which is in turn based on the 1913 US Webster’s Unabridged Dictionary (See Project Gutenburg), as a text file.