1: great wickedness
2: an outrageous or immoral act or offense
3 : very large size
4 : the quality of great impact or importance
Although "enormity" has been used since the late 1700s to denote large size, this usage continues to be disparaged by various language commentators who argue that "enormity" should be reserved for senses related to "great wickedness." It is "enormousness," they insist (a hefty and considerably less common word), that should be used in reference to great size, despite the fact that, like "enormity," it too originally was used to denote wickedness or divergence from accepted moral standards. For better or worse, this proscription has been widely ignored by many English speakers, including professional writers. However one chooses to use them, "enormity" and "enormous" can both be traced back to the Latin "enormis," from the prefix "e-" ("out of") and "norma" ("rule," "pattern," or "carpenter's square").