The Collaborative International Dictionary of English v.0.48:

Slush \Slush\ (sl[u^]sh), n. [Cf. Sw. slaska to paddle in water,
   slask wet, filth.] [Written also slosh.]
   1. Soft mud.
      [1913 Webster]

   2. A mixture of snow and water; half-melted snow.
      [1913 Webster]

   3. A soft mixture of grease and other materials, used for
      lubrication.
      [1913 Webster]

   4. The refuse grease and fat collected in cooking, especially
      on shipboard.
      [1913 Webster]

   5. (Mach.) A mixture of white lead and lime, with which the
      bright parts of machines, such as the connecting rods of
      steamboats, are painted to be preserved from oxidation.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Slush \Slush\ (sl[u^]sh), v. t. [imp. & p. p. Slushed; p. pr.
   & vb. n. Slushing.]
   1. To smear with slush or grease; as, to slush a mast.
      [1913 Webster]

   2. To paint with a mixture of white lead and lime.
      [1913 Webster]

WordNet (r) 3.0 (2006):

slush
    n 1: partially melted snow
    v 1: make a splashing sound; "water was splashing on the floor"
         [syn: splash, splosh, slosh, slush]
    2: spill or splash copiously or clumsily; "slosh paint all over
       the walls" [syn: slosh, slush, slosh around, slush
       around]