The Collaborative International Dictionary of English v.0.48:

Milk \Milk\ (m[i^]lk), n. [AS. meoluc, meoloc, meolc, milc; akin
   to OFries. meloc, D. melk, G. milch, OHG. miluh, Icel.
   mj[=o]lk, Sw. mj["o]lk, Dan. melk, Goth. miluks, G. melken to
   milk, OHG. melchan, Lith. milszti, L. mulgere, Gr.
   'ame`lgein. [root]107. Cf. Milch, Emulsion, Milt soft
   roe of fishes.]
   [1913 Webster]
   1. (Physiol.) A white fluid secreted by the mammary glands of
      female mammals for the nourishment of their young,
      consisting of minute globules of fat suspended in a
      solution of casein, albumin, milk sugar, and inorganic
      salts. "White as morne milk." --Chaucer.
      [1913 Webster]

   2. (Bot.) A kind of juice or sap, usually white in color,
      found in certain plants; latex. See Latex.
      [1913 Webster]

   3. An emulsion made by bruising seeds; as, the milk of
      almonds, produced by pounding almonds with sugar and
      water.
      [1913 Webster]

   4. (Zool.) The ripe, undischarged spat of an oyster.
      [1913 Webster]

   Condensed milk. See under Condense, v. t.

   Milk crust (Med.), vesicular eczema occurring on the face
      and scalp of nursing infants. See Eczema.

   Milk fever.
      (a) (Med.) A fever which accompanies or precedes the first
          lactation. It is usually transitory.
      (b) (Vet. Surg.) A form puerperal peritonitis in cattle;
          also, a variety of meningitis occurring in cows after
          calving.

   Milk glass, glass having a milky appearance.

   Milk knot (Med.), a hard lump forming in the breast of a
      nursing woman, due to obstruction to the flow of milk and
      congestion of the mammary glands.

   Milk leg (Med.), a swollen condition of the leg, usually in
      puerperal women, caused by an inflammation of veins, and
      characterized by a white appearance occasioned by an
      accumulation of serum and sometimes of pus in the cellular
      tissue.

   Milk meats, food made from milk, as butter and cheese.
      [Obs.] --Bailey.

   Milk mirror. Same as Escutcheon, 2.

   Milk molar (Anat.), one of the deciduous molar teeth which
      are shed and replaced by the premolars.

   Milk of lime (Chem.), a watery emulsion of calcium hydrate,
      produced by macerating quicklime in water.

   Milk parsley (Bot.), an umbelliferous plant (Peucedanum
      palustre) of Europe and Asia, having a milky juice.

   Milk pea (Bot.), a genus (Galactia) of leguminous and,
      usually, twining plants.

   Milk sickness (Med.), See milk sickness in the
      vocabulary.

   Milk snake (Zool.), a harmless American snake (Ophibolus
      triangulus, or Ophibolus eximius). It is variously
      marked with white, gray, and red. Called also milk
      adder, chicken snake, house snake, etc.

   Milk sugar. (Physiol. Chem.) See Lactose, and Sugar of
      milk (below).

   Milk thistle (Bot.), an esculent European thistle (Silybum
      marianum), having the veins of its leaves of a milky
      whiteness.

   Milk thrush. (Med.) See Thrush.

   Milk tooth (Anat.), one of the temporary first set of teeth
      in young mammals; in man there are twenty.

   Milk tree (Bot.), a tree yielding a milky juice, as the cow
      tree of South America (Brosimum Galactodendron), and the
      Euphorbia balsamifera of the Canaries, the milk of both
      of which is wholesome food.

   Milk vessel (Bot.), a special cell in the inner bark of a
      plant, or a series of cells, in which the milky juice is
      contained. See Latex.

   Rock milk. See Agaric mineral, under Agaric.

   Sugar of milk. The sugar characteristic of milk; a hard
      white crystalline slightly sweet substance obtained by
      evaporation of the whey of milk. It is used in pellets and
      powder as a vehicle for homeopathic medicines, and as an
      article of diet. See Lactose.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Milk sickness \Milk sickness\ (Veter., Med.)
   A peculiar malignant disease, occurring in parts of the
   western United States, and affecting certain kinds of farm
   stock (esp. cows), and persons using the meat or dairy
   products of infected cattle. Its chief symptoms in man are
   uncontrollable vomiting, obstinate constipation, pain, and
   muscular tremors. Its origin in cattle has been variously
   ascribed to the presence of certain plants in their food, and
   to polluted water.
   [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

milk sickness
    n 1: disease of livestock and especially cattle poisoned by
         eating certain kinds of snakeroot [syn: trembles, milk
         sickness]
    2: caused by consuming milk from cattle suffering from trembles