Date: 15th century
1. an outrageous, improper, vicious, or immoral act <the enormities of state power — Susan Sontag> <other enormities too juvenile to mention — Richard Freedman> 2. the quality or state of being immoderate, monstrous, or outrageous; especially great wickedness <the enormity of the crimes committed during the Third Reich — G. A. Craig> 3. the quality or state of being huge ; immensity <the inconceivable enormity of the universe> 4. a quality of momentous importance or impact <the enormity of the decision> Usage: Enormity, some people insist, is improperly used to denote large size. They insist on enormousness for this meaning, and would limit enormity to the meaning “great wickedness.” Those who urge such a limitation may not recognize the subtlety with which enormity is actually used. It regularly denotes a considerable departure from the expected or normal <they awakened; they sat up; and then the enormity of their situation burst upon them. “How did the fire start?” — John Steinbeck>. When used to denote large size, either literal or figurative, it usually suggests something so large as to seem overwhelming <no intermediate zone of study. Either the enormity of the desert or the sight of a tiny flower — Paul Theroux> <the enormity of the task of teachers in slum schools — J. B. Conant> and may even be used to suggest both great size and deviation from morality <the enormity of existing stockpiles of atomic weapons — New Republic>. It can also emphasize the momentousness of what has happened <the sombre enormity of the Russian Revolution — George Steiner> or of its consequences <perceived as no one in the family could the enormity of the misfortune — E. L. Doctorow>.
New Collegiate Dictionary. 2001.