unicorn

We all know a unicorn is a mythical creature resembling a horse with a single horn projecting from its forehead, but the term has some quite interesting slang uses. The word comes to English via Anglo-Norman, the variety of French spoken in England after the Norman conquest, and ultimately from the Latin unicornis, uni- (one) + cornu (horn).

The earliest appearance of unicorn in English is in the text Ancren Riwle, a monastic manual for female anchorites, written c. 1230:

Wreaððe is a forschuppilt, as me teleð I spelles, for ha reueð mon his wit ant changeð al his chere, ant forshuppeð him from mon into beastes cunde. Wummon wrað is wuluene; Mon wulf oðer liun oðer unicorne.

(Wrath is a shape-shifter, as it is depicted in tales, for it takes from a man his reason and changes his countenance, and transforms him from a man into the nature of a beast. A woman’s wrath is wolf-like; man’s is wolf, or lion, or unicorn.)

Common medieval typology had the unicorn representing anger or wrath, especially the wrath of God, which was tamed by Christ, represented as a virgin. Hence the myths about maidens taming unicorns.  Medieval texts almost invariably represented unicorns as male; evidently there were no female unicorns. The unicorn’s horn and the spears that penetrate the beast’s flesh during a unicorn hunt are phallic and a commentary on virginity and temptation.

Middle English translations of the Bible and various bestiaries used the word unicorn as the name for the rhinoceros, not a mythical or symbolic beast at all. These were translations of either the Latin unicornis, the Greek μονόκερως (monoceros). From a 1382 Wycliffite translation of Numbers 23:22:

The Lord God hath ladde hym out of Egipte, whos strengthe is lijk to an vnycorn.

The translator here was working from Jerome's Vulgate text which uses the word rinocerotis. Modern translations tend to render the term in this passage, the Hebrew רְאֵם (rĕ’ēm), as “wild ox.”

But in present-day slang, unicorn is used to refer to something that is highly sought after but extremely rare and perhaps non-existent—not unlike the medieval unicorn. For instance, this sense appeared in the Los Angeles Times in April 1987 about the search for extra-terrestrial life:

[Robert] Rood, professor of astronomy at the University of Virginia, was giving the people what they presumably wanted. Speaking Friday at the annual conference of the Committee for the Scientific Investigation of Claims of the Paranormal, a national organization of skeptics, he sought to “cast some sees of doubt” regarding the international network of Search for Extraterrestrial Intelligence, which is listening for intergalactic radio transmissions.

[…]

Two scientists who have participated in the activities, sometimes wincing at Rood’s jabs, defended their beliefs in extraterrestrial life. It is a matter of overwhelming probabilities, they said, that other planets in the universe have life forms as advanced as ours.

“We’re not looking for unicorns but something we know very well exists—evidence of another technology,” said Jill Tartar, research astronomer at University of California, Berkeley.

This general slang sense has spawned several specific applications of the word. One such comes to us out of Silicon Valley, where a unicorn is a software startup that is valued at over $1 billion dollars, what every venture capitalist wants to find. Unlike most slang usages, we can pinpoint an exact origin for this particular definition. Venture capitalist Aileen Lee used this sense in a blog post in November 2013:

We found 39 companies belong to what we call the “Unicorn Club” (by our definition, U.S.-based software companies started since 2003 and valued at over $1 billion by public or private market investors).

An older and very different slang sense is sexual in nature. The word has been used to refer to bisexual men, a mythical creature in the eyes of those who think men must be either straight or gay. This sense appears in The Advocate as early as 2007:

“I’m a unicorn.” That’s what I may as well have said to the handsome man sitting across the table from me. We were on our first date, having “met” on MySpace. Thanks to his online profile, I already knew he was competing for the title Mr. Gay Universe, that he often frequented pool parties wearing nothing but purple paint and a few strategically placed sequins, that the wrote poems a first-grader would call puerile. Even so, it was he who regarded me as a potential embarrassment.

“I’m bisexual” is what I actually said.

His response, i.e., repulsion barely masked as fascination, was one I've become accustomed to. I'm not alone. Other members of society—alcoholics, ex-convicts, cast members of Diff'rent Strokes—all face similar skepticism when revealing personal information to new acquaintances. People simply don't trust us.

Or they claim that, like a unicorn, we don't exist. Were I to include an online poll with this article, I'm willing to bet most of you believe we're more likely to suddenly find weapons of mass destruction in Iraq than a true bisexual.

The term is also used to refer to a bisexual person, and unlike the medieval unicorn usually female, who is willing to have sex with a couple with no strings attached. Urban Dictionary records this sense from 16 February 2004:

Young girls that have three ways with couples (woman and a man)

Hubbie and I are still looking for our Unicorn.

The word has come a long way from referring to a creature that only a virgin can tame.

Sources:

Brother, Job. “Fairy Tales.” The Advocate, 1 October 2007.

Forshall, Josiah and Frederic Madden, eds. The Holy Bible, Containing the Old and New Testaments, with the Apocryphal Books, in the Earliest English Versions Made from the Latin Vulgate by John Wycliffe and his Followers, vol. 1. Oxford: Oxford UP, 1850, Numbers 23:22, 430. Archive.org.

Green’s Dictionary of Slang, accessed 15 August 2025, s.v. unicorn, n.

Lee, Aileen. “Welcome to the Unicorn Club: Learning from Billion-Dollar Startups.” TechCrunch, 2 November 2013.

Middle English Dictionary, 4 March 2025, s.v. unicorn(e, n.

Millett, Bella, ed. Ancrene Wisse. A Corrected Edition of the Text in Cambridge, Corpus Christi College, MS 401, with Variants from Other Manuscripts. Early English Text Society 325. Oxford: Oxford UP, 2005, 48. Cambridge, Corpus Christi College, MS 402, fol. 32v. Archive.org.

Newton, Edmund. “Skeptics Spar with Scientists Seeking ETs.” Los Angeles Times, 5 April 1987, Part II-AR 11/1–2. ProQuest Historical Newspapers.

Oxford English Dictionary Online, 1924, s.v. unicorn, n.

Urbandictionary.com, 16 February 2004, s. v. unicorn.