When published in 1755, the letter X was left out of Johnson’s Dictionary with the claim that X “begins no word in the English language.” Historically, words like xylophone and xenophobia didn’t enter the English lexicon until the 19th century. Today, the Oxford English Dictionary (OED) contains about 400 words that begin with X. Compare this to the letter S with 79,900+ words! Nonetheless, where X may fall short in word count, it packs a punch as a symbol, a classifier, and in popular culture.
History and Phonology
Briefly, X is derived from the Phoenician letter samekh, meaning “fish” and denoted a hard /s/ sound. The Greeks borrowed the samekh, named it Chi, and used it for the digraph /ks/. The Romans took Chi from Greek alphabets for their letter X and the numeral “10.” Old English adopted the Roman alphabet where it eventually replaced the German runic alphabet around the 7th century. This orthographic relay spans about 1,800 years of history. Since the medieval period, we’ve been using X and the Roman alphabet for almost fourteen centuries.
X is a bit of a phonetic chameleon when it comes to spelling and pronunciation in English. X is used for the digraph /ks/ in words such as wax and fox. In words like auxiliary and exhaust, the X changes to a /gz/ sound. X can also be a /z/ sound (xylophone), a hard /k/ sound (excite), and a /kzh/ sound (luxury). X can be silent as well, as in Sioux or the French loan-word faux.
The letter X is used in a variety of commercial, academic, social, and religious contexts. We rely on these contexts to tell us whether to engage with the letter as a sound, a classifier, or a symbol. Below is a long short-list that exemplifies the power of X.
Mathematics
- An independent or unknown value in algebraic algorithms, x + 5 = 0, x = -5
- The horizontal axis on a Cartesian coordinate system
- Roman numeral for 10, e.g., LXII
- Multiplication symbol; 3 x 5 = 15, pronounced ‘times’
- Dimension; 3 x 5 card, pronounced ‘by’
- Power; e.g., 50x telescope
Science
- Botanical hybrids; iris x germanica
- Out of, foaled by, as in “a colt by Secretariat x Merrylegs“
- Non-binary gender; M/F/X
- Chromosome provided by the female ovum; XX=female, XY=male
- Stands for any halogen group in organic chemistry
- Rx; prescription, Latin for “recipe”
- Branding in pharmaceuticals; Sominex, Xylocaine, Xanax; Vitamin X (Ecstasy), a rave and dance-club drug
- Indicates “experimental” in the aerospace industry and Google [x], an innovation arm of Alphabet, Inc.
History
- Meaning ‘between’ in historical dating; 1483 x 1485
Sports & Gaming
- A capture in chess
- A strike in baseball and bowling
- A defensive player on a football-play diagram
- One of two players in tic-tac-toe, X and O
- Indicating ‘extreme,’ as in X-Sports
- Incorrect, missed, not allowed
Religion
- Denotes “Christ” in Xtian and Xmas
- Symbol of dark arts, black magic, witchcraft and occults
Commercial, Manufacturing & Branding
- In advertising, a trade term for a generic version; Brand X
- Denotes “trans” as in XMIT or XFER and “cross” in X-ing and XREF
- Alcoholic strength, such as moonshine; XXX (150 proof)
- Level of eroticism, violence, or offensive language, as in the movie rating, Rated X, and pornography
- Indicating ‘extra’ in clothing sizes as in XXL, XS
- Signifies excellence or precision; Jaguar X, Xbox, Model X
- X-factor, entertainment industry term indicating star quality (now associated with the television musical talent show)
- A placeholder in airport codes; LAX
Popular Culture & Social Contexts
- Unknown or secret; Malcolm X, Project X, X-ray, X-files, Planet X, Agent X, Camp X
- Generation X; 10th generation of Americans since 1776
- A collaboration in arts or fashion; Smith x Brown
- X ‘marks the spot’ for labeling a specific location or scene of a crime
- Choice or position on a ballot, survey, or test with multiple options
- Serves as a signature for illiteracy and a place marker for a signature or initials, x______________
- To delete
- A promise; crossed heart
- A lie; crossed fingers
- A “kiss” in correspondence
- Indicates “no beer, no drugs, no promiscuous sex;” XXX
- Denotes death or ‘out cold’ in cartoon drawings with X’s for eyes
- Rebel, piracy, and a symbol of a skull and crossbones
Not included in the above list are the myriad national flags, songs, bands, albums, books, advertisements, commercial products, paintings, and movies that have included X as part of their symbology.
If you enjoyed reading about X, you might also be interested in the surprising facts about S, Z, E, and the R sound in English!
Go to the previous or next Fun Facts About English.
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