Deviation or departure from the normal or common order, form, or rule.
One that is peculiar, irregular, abnormal, or difficult to classify: "Both men are anomalies: they have . . . likable personalities but each has made his reputation as a heavy"(David Pauly).
Astronomy The angular deviation, as observed from the sun, of a planet from its perihelion.
[uh-nom-uh-lis-tik] 
əˈlɪs