The history of ‘nightmare’

The 'mare' has many meanings

People awakening from a “nightmare” often have the sensation that they can’t breathe. Not surprising: That’s where the word “nightmare” comes from.

The Oxford English Dictionary traces the first used of “nightmare” in English to around 1300, as “a female spirit or monster supposed to settle on and produce a feeling of suffocation in a sleeping person or animal.”

Other folk etymology traces the “mare” of the night in some similar linguistic form all the way to our earliest languages as humans. We’ve always had evil spirits.

Since we experience most “nightmares” at night, and with the perception that death and other bogies haunt the darkness, “night” was naturally paired with “mare,” which traces in English to before the 12th century. A “nightmare” soon came to mean any bad dream, whether accompanied by that suffocating feeling or not.

Unfortunately, “nightmares” don’t just happen at night, or just during sleep. A tie-up on the freeway can cause a “nightmare” commute, and a difficult boss can be a “nightmare” to deal with. The stiffer-upper-lip British OED calls those uses “colloquial” and “weakened use,” but American dictionaries are fine with it.

While some think that a “nightmare” took the form of a female horse, or that the evil spirit “mare” was somehow related to the horse, they actually developed separately. “Mare” was originally a horse of either sex; it soon became the female of any equine, including zebras, donkeys, and mules. The “mare” of “nightmare” had a distinct meaning, though you can forgive people for not recognizing the difference. After all, we can have a “mole” on the skin, and a different kind of “mole” digging in the yard.

English, after all, is a “mare’s nest” of contradictions and mysteries.

That “mare,” though, has nothing to do with evil spirits. Most people use “mare’s nest” to mean a muddle or tangle, such as a complicated story line in a book or movie, or red tape. That “mare” is the female horse, whose “nest” is an untidy pile of straw.

But wait, you say, horses don’t have “nests,” do they?

Well, no. And that’s a clue to the original meaning of “mare’s nest”: a misperception, specifically “a hoax or fraud or some other nonexistent or illusory thing that seems at first to be very wonderful and full of promise but that ultimately brings ridicule on those deceived by it,” as M-W puts it.

As explained by the wonderful Phrase Finder blog: “The earlier ‘misconception’ meaning has been in use since at least the 16th century.” But, of course, the blog says, “mares don’t make nests — the allusion was meant to be comically ironic. That humour is reflected in several of the early citations of ‘mare’s nest’ (or horse’s nest, as some early references have it), which refer directly to laughter.”

The Dictionary of the Vulgar Tongue, published in 1811, for example, has this entry: “He has found a mare’s nest, and is laughing at the eggs; said of one who laughs without any apparent cause.”

The sense of a “mare’s nest” to mean a complicated tangle did not arise until the mid-19th century, the OED says. Many etymologists attribute it to its similarity to a “rat’s nest,” said to be untidy and perhaps even unsafe.

Of course, a “rat’s nest” is no more untidy than anyone else’s nest. So perhaps the belief that a “rat’s nest” is a bad thing is a “mare’s nest,” in the original sense.

Time to rein it in, we think, before we get further entangled.


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Merrill Perlman managed copy desks across the newsroom at The New York Times, where she worked for 25 years. Follow her on Twitter at @meperl.