10th letter of the English alphabet, pronounced "jay," as in "kay" for -k-, but formerly written out as jy, rhyming with -i- and corresponding to French ji.

One of the most stable English letters (it has almost always the same sound), it is a latecomer to the alphabet and originally had no sound value. The letter itself began as a scribal modification of Roman -i- in continental Medieval Latin. The scribes added a "hook" to small -i-, especially in the final position in a word or roman numeral, to distinguish it from the strokes of other letters. The dot on the -i- (and thus the -j-) and the capitalization of the pronoun I are other solutions to the same problems.

In English, -j- was used as a roman numeral throughout Middle English, but the letter -y- was used to spell words ending an "i" sound, so -j- was not needed to represent a sound. Instead, it was introduced into English c. 1600-1640 to take up the consonantal sound that had evolved from the Roman i- since Late Latin times. In Italian, g- was used to represent this, but in other languages j- took the job. This usage is attested earliest in Spanish, where it was in place before 1600.

No word beginning with J is of Old English derivation. [OED]

English dictionaries did not distinguish words beginning in -i- and -j- until 19c., and -j- formerly was skipped when letters were used to express serial order.

In Latin texts printed in modern times, -j- often is used to represent Latin -i- before -a-, -e-, -o-, -u- in the same syllable, which in Latin was sounded as the consonant in Modern English you, yam, etc., but the custom has been controversial among Latinists:

The character J, j, which represents the letter sound in some school-books, is an invention of the seventeenth century, and is not found in MSS., nor in the best texts of the Latin authors. [Lewis]

In English words from Hebrew, -j- represents yodh, which was equivalent to English consonantal y (hence hallelujah) but many of the Hebrew names later were conformed in sound to the modern -j- (compare Jesus).

1813, "to thrust or strike with a point," a Scottish variant of job "to strike, pierce, thrust," from Middle English jobben "to jab, thrust, peck" (c. 1500), a word of unknown origin, perhaps imitative. Related: Jabbed; jabbing.

1825, "a thrust or poke with the point of something," from jab (v.). Meaning "a punch with the fist" is from 1889. Sense of "injection with a hypodermic needle," once beloved by newspaper headline writers, is from 1914.

"talk rapidly and indistinctly," 1650s, spelling variant of Middle English jablen (c. 1400), also javeren, jaberen, chaveren, jawin; probably ultimately echoic. Related: Jabbered; jabbering. The noun, "rapid, unintelligible talk" is 1727, from the verb. Related: Jabberment (Milton).

1871, nonsense word (perhaps based on jabber) coined by Lewis Carroll, for the poem of the same name, which he published in "Through the Looking-Glass." The poem is about a fabulous beast called the Jabberwock.

1823, "frill of a men's shirt," from French jabot "gizzard (of a bird), frill on a shirt front" (16c.), a word of unknown origin. Klein suggests a connection with gaver "to cram, gorge," and thus ultimately with English jaw (n.). Of women's clothing from 1869.

c. 2000, professional wrestling slang for one whose main purpose is to make the better-known wrestlers of the organization look good; he or she does this by losing to them. More commonly known as a jobber, in a specialized sense of that word (though some enthusiasts claim there is a difference), and perhaps a mock-Italianized form of that word (but compare jaboney "naive person; immigrant; hoodlum," a word of unknown origin, in American English use c. 1990). Formerly in pugilism slang such a fighter was a set-up (by 1926).

Jobber — A performer who regularly loses on television and doesn't receive much if any push. A comparable term for such a performer is jabroni, which is a favorite catch-phrase of Dwayne "The Rock" Johnson. To soften the blow of such labels, some wrestling promotions refer to jobbers as enhancement talent. Carpenter was the phrase used by earlier generations. ["The Professional Wrestlers' Instructional and Workout Guide," 2005]

tropical American tree, 1753, from Portuguese jacarandá, from Tupi yacaranda.

French, literally "I accuse," a phrase made famous by Emile Zola in a public letter (published Jan. 13, 1898) attacking the irregularities of the Dreyfus trial.

c. 1200, a blue gem (occasionally a red one), from Old French jacinte, iacinte "hyacinth; jacinth," or directly from Late Latin iacintus (see hyacinth). In modern use, a reddish-orange gem. The word is hyacinth with the h- lost and the initial -i- made consonantal.