blackjack

• black jack, black-jack

From black + jack.

• enPR: blăk'jăk, IPA^(key): /ˈblækd͡ʒæk/

• Audio (Southern England):

  (file)

blackjack (countable and uncountable, plural blackjacks)

1. (card games) A common gambling card game in casinos, where the object is to get as close to 21 without going over.

   Synonyms: pontoon, twenty-one, vingt-et-un

2. (card games) A hand in the game of blackjack consisting of a face card and an ace.
3. (card games) A variant of switch where each player is initially dealt the same number of cards, usually seven, and when one player plays a black jack the player whose turn comes next has to pick up that many cards, unless they play a red jack (as this normally cancels a black jack).
4. (card games) A variant of hearts where the Jack of Spades is the penalty card.
5. The flag (i.e., a jack) traditionally flown by pirate ships; popularly thought to be a white skull and crossed bones on a black field (the Jolly Roger).
6. (weaponry) A small, flat, blunt, usually leather-covered weapon loaded with heavy material such as lead or ball bearings, intended to inflict a blow to the head that renders the victim unconscious with diminished risk of lasting cranial trauma.

   Coordinate terms: baton, cosh, sap

   • 2016, Justin O. Schmidt, The Sting of the Wild, Johns Hopkins University Press,, →ISBN, page 131:

     The pain is sometimes like the dull, heavy thud of being hit with a lead-filled blackjack; other times like a wizard is reaching deep below the skin and ripping muscles, tendons, and nerves.

7. (aviation) A tool of leather filled with shot (or similar), resembling the weapon, used for shaping sheet metal.
8. Any of several species of weed of genus Bidens, such as Bidens pilosa, in the family Compositae.
9. Ellipsis of blackjack oak.
   • 1930, Edna Ferber, Cimarron, page 23:

     A little creek ran through the land, and the prairie rolled a little there, too. Nothing but blackjacks for miles around it, but on that section, because of the water, I suppose, there were elms and persimmons and cottonwoods and even a grove of pecans.

   • 1931, William Faulkner, Sanctuary, Library of America, published 1985, page 20:

     A steep slope rose, crested by stunted blackjacks.

10. Any of a series of hard, dark soils, often considered low quality, but suitable for growing certain crops such as cotton.
    • 1859, Henry Ward Beecher, Plain and Pleasant Talk about Fruits, Flowers, and Farming, page 216:

      This man had a brother about six miles off, settled on a rich White River bottom-land farm -- and while a blackjack clay soil yielded seventy bushels to the acre, this fine bottom-land would not average fifty.

    • 1884, United States Census Office, Census Reports: Tenth Census: June 1, 1880: Cotton production in the United States, page 20:

      Blackjack soil is generally the poorest of all; it covers the narrow and rocky ridges, and has a stunted growth of blackjack and post oaks. The soil is dark in color, thin and cold, and is underlaid with pale yellow or slate-colored clay.

    • 1911, Field Operations of the Bureau of Soils, page 1871:

      The predominant soil is the blackjack soil like that of the lower plateaus, seemingly, however, in most cases a little more sandy and a little coarser in grain.

    • 2010, Gary Mark Fleeger, Steven J. Whitmeyer, The Mid-Atlantic Shore to the Appalachian Highlands: Field Trip Guidebook for the 2010 Joint Meeting of the Northeastern and Southeastern GSA Sections, Geological Society of America, →ISBN, page 48:

      Today, most types of land development in areas underlain by Iredell and related “blackjack” soil series—a catch-all term for Jackland, Whitestore, Orange, Zion, and other high shrink-swell clayey soils—is generally discouraged.

    • 2011, Michael Eury, Concord, Arcadia Publishing, →ISBN:

      Cotton grew robustly in western Cabarrus County's blackjack soil, pointing Concord beyond its agricultural base toward its first industry: textiles.

11. (pharmacology, UK, Australia, rare) Ammonium bituminosulfonate.
    • 1914 October 11, The Sunday Times, Perth, Australia, page 1, column 9:

      "Next!" steps gingerly in to confront the medical eye fastened questioningly upon him. "Crook in the guts," he says tersely. The picturesque reports of previously treated and disgusted patients - have left him doubtful, and he casts, an anathematising eye upon the "Black Jack" bottle. "Tabloids and duty!" says the doctor, and the sufferer sighs with relief.

    • 2010 October 19, John Davies, birminghamhistory.co.uk‎^[1]:

      I remember Black Jack very well and actually like the smell. It is no longer available with that trade name but glycerine of ichthammol can still be bought in chemists.

    • 2008 September 19, stef240377, MoneySavingExpert.com‎^[2]:

      Used to be called Black Jack think my mom had an ancient jar in her medicine cupboard.

• → Polish: blackjack

blackjack (third-person singular simple present blackjacks, present participle blackjacking, simple past and past participle blackjacked)

1. To strike with a blackjack or similar weapon.
   • 2019, Ta-Nehisi Coates, The Water Dancer, Penguin Books (2020), page 233:

     “We cannot have you getting blackjacked and bound yet again.”

• baccarat
• bludgeon
• cosh
• pontoon
• truncheon
• twenty-one

• “blackjack”, in OneLook Dictionary Search.
• blackjack on Wikipedia.Wikipedia
• blackjack (weapon) on Wikipedia.Wikipedia

From English blackjack.

• IPA^(key): /ˈblækdʒæk/, [ˈblæk.dʒæk]
• Rhymes: -ækdʒæk

blackjack

1. blackjack (card game)
2. blackjack (hand in that game)

• black jack

Unadapted borrowing from English blackjack.

• IPA^(key): /blɛɡˈd͡ʐɛk/
• Rhymes: -ɛk
• Syllabification: black‧jack

blackjack m animal

1. (card games) blackjack (common gambling card game in casinos, where the object is to get as close to 21 without going over)

• “blackjack”, in Wielki słownik języka polskiego‎^[3] (in Polish), Instytut Języka Polskiego PAN
• “blackjack”, in Polish dictionaries at PWN‎^[4] (in Polish)

• • Rhymes: -aɡʝak

• • Rhymes: -ak
• Syllabification: black‧jack

blackjack m (plural blackjacks)

1. blackjack (card game)

• “blackjack”, in Diccionario de la lengua española [Dictionary of the Spanish Language] (in Spanish), online version 23.8.1, Royal Spanish Academy [Spanish: Real Academia Española], 15 December 2025