black jack

from The Collaborative International Dictionary of English v.0.48

Scaup \Scaup\ (sk[add]p), n. [See {Scalp} a bed of oysters or
   mussels.]
   1. A bed or stratum of shellfish; scalp. [Scot.]
      [1913 Webster]

   2. (Zool.) A scaup duck. See below.
      [1913 Webster]

   {Scaup duck} (Zool.), any one of several species of northern
      ducks of the genus {Aythya}, or {Fuligula}. The adult
      males are, in large part, black. The three North American
      species are: the greater scaup duck ({Aythya marila}, var.
      nearctica), called also {broadbill}, {bluebill},
      {blackhead}, {flock duck}, {flocking fowl}, and {raft
      duck}; the lesser scaup duck ({Aythya affinis}), called
      also {little bluebill}, {river broadbill}, and {shuffler};
      the tufted, or ring-necked, scaup duck ({Aythya
      collaris}), called also {black jack}, {ringneck},
      {ringbill}, {ringbill shuffler}, etc. See Illust. of
      {Ring-necked duck}, under {Ring-necked}. The common
      European scaup, or mussel, duck ({Aythya marila}), closely
      resembles the American variety.
      [1913 Webster]

from The Collaborative International Dictionary of English v.0.48

Jack \Jack\, n. [Named from its resemblance to a jack boot.]
   A pitcher or can of waxed leather; -- called also {black
   jack}. [Obs.] --Dryden.
   [1913 Webster]

from The Collaborative International Dictionary of English v.0.48

Ring-necked \Ring"-necked`\, a. (Zool.)
   Having a well defined ring of color around the neck.
   [1913 Webster]

   {Ring-necked duck} (Zool.), an American scaup duck ({Aythya
      collaris}). The head, neck, and breast of the adult male
      are black, and a narrow, but conspicuous, red ring
      encircles the neck. This ring is absent in the female.
      Called also {ring-neck}, {ring-necked blackhead},
      {ringbill}, {tufted duck}, and {black jack}.
      [1913 Webster]

from U.S. Gazetteer (1990)

Black Jack, MO (city, FIPS 6004)
  Location: 38.79815 N, 90.26360 W
  Population (1990): 6128 (2076 housing units)
  Area: 6.9 sq km (land), 0.0 sq km (water)

from U.S. Gazetteer Places (2000)

Black Jack, MO -- U.S. city in Missouri
   Population (2000):    6792
   Housing Units (2000): 2587
   Land area (2000):     2.660066 sq. miles (6.889540 sq. km)
   Water area (2000):    0.007305 sq. miles (0.018921 sq. km)
   Total area (2000):    2.667371 sq. miles (6.908461 sq. km)
   FIPS code:            06004
   Located within:       Missouri (MO), FIPS 29
   Location:             38.790799 N, 90.261885 W
   ZIP Codes (1990):    
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Black Jack, MO
    Black Jack