Recently on Twitter, Mark Allen wrote, “Despite once being synonyms, ‘enormity’ and ‘enormousness’ are different. Try to keep ‘enormity’ for something evil or outrageous.” I’ll admit right off that this usage problem interests me because I didn’t learn about the distinction until a few years ago. To me, they’re completely synonymous, and the idea of using enormity to mean “an outrageous, improper, vicious, or immoral act” and not “the quality or state of being huge”, as Merriam-Webster defines it, seems almost quaint.
Of course, such usage advice presupposes that people are using the two words synonymously; if they weren’t, there’d be no reason to tell them to keep the words separate, so the assertion that they’re different is really an exhortation to make them different. Given that, I had to wonder how different they really are. I turned to Mark Davies Corpus of Contemporary American English to get an idea of how often enormity is used in the sense of great size rather than outrageousness or immorality. I looked at the first hundred results from the keyword-in-context option, which randomly samples the corpus, and tried to determine which of the four Merriam-Webster definitions was being used. For reference, here are the four definitions:
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>>
In some cases it was a tough call; for instance, when someone writes about the enormity of poverty in India, enormity has a negative connotation, but it doesn’t seem right to substitute a word like monstrousness or wickedness. It seems that the author simply means the size of the problem. I tried to use my best judgement based on the context the corpus provides, but in some cases I weaseled out by assigning a particular use to two definitions. Here’s my count:
By far the most common use is in the sense of “enormousness”; the supposedly correct senses of great wickedness (definitions 1 and 2) are used just under a quarter of the time. So why did Mr. Allen say that enormity and enormousness were once synonyms? Even the Oxford English Dictionary marks the “enormousness” sense as obsolete and says, “Recent examples might perh. be found, but the use is now regarded as incorrect.” Perhaps? It’s clear from the evidence that it’s still quite common—about three times as common as the prescribed “monstrous wickedness” sense.
It’s true that the sense of immoderateness or wickedness came along before the sense of great size. The first uses as recorded in the OED are in the sense of “a breach of law or morality” (1477), “deviation from moral or legal rectitude” (1480), “something that is abnormal” (a1513), and “divergence from a normal standard or type” (a1538). The sense of “excess in magnitude”—the one that the OED marks as obsolete and incorrect—didn’t come along until 1792. In all these senses the etymology is clear: the word comes from enorm, meaning “out of the norm”.
As is to be expected, Merriam-Webster’s Dictionary of English Usage has an excellent entry on the topic. It notes that many of the uses of enormity considered objectionable carry shades of meaning or connotations not shown by enormousness:
Quite often enormity will be used to suggest a size that is beyond normal bounds, a size that is unexpectedly great. Hence the notion of monstrousness may creep in, but without the notion of wickedness. . . .
In many instances the notion of great size is colored by aspects of the first sense of enormity as defined in Webster’s Second. One common figurative use blends together notions of immoderateness, excess, and monstrousness to suggest a size that is daunting or overwhelming.
Indeed, it’s the blending of senses that made it hard to categorize some of the uses that I came across in COCA. Enormousness does not seem to be a fitting replacement for those blended or intermediate senses, and, as MWDEU notes, it’s never been a popular word anyway. Interestingly, MWDEU also notes that “the reasons for stigmatizing the size sense of enormity are not known.” Perhaps it became rare in the 1800s, when the OED marked it obsolete, and the rule was created before the sense enjoyed a resurgence in the twentieth century. Whatever the reason, I don’t think it makes much sense to condemn the more widely used sense of a word just because it’s newer or was rare at some point in the past. MWDEU sensibly concludes, “We have seen that there is no clear basis for the ‘rule’ at all. We suggest that you follow the writers rather than the critics: writers use enormity with a richness and subtlety that the critics have failed to take account of. The stigmatized sense is entirely standard and has been for more than a century and a half.”