The Collaborative International Dictionary of English v.0.48:

Smoker \Smok"er\, n.
   1. One who dries or preserves by smoke.
      [1913 Webster]

   2. One who smokes tobacco or the like.
      [1913 Webster]

   3. A smoking car or compartment. [U. S.]
      [1913 Webster]

   4. A gathering for smoking and social intercourse. [Colloq.]

            That evening A Company had a "smoker" in one of the
            disused huts of Shorncliffe Camp.     --Strand Mag.
      [Webster 1913 Suppl.]

   black smoker, a vent at the bottom of the ocean, usually at
      a mid-ocean ridge, through which large quantities of water
      carrying minerals flow, producing a jet of fluid with the
      appearance of black smoke. The ocean water in crevices
      below the vent is heated to temperatures near 400[deg] C,
      and dissolves quantities of metal salts, such as of
      copper, zinc, gold, and manganese. When the saturated
      mineral solutions exit the vent, cooling by contact with
      the ocean causes the metals to precipitate, mainly as
      sulfide or sulfate salts. Unusual forms of life such as
      tube worms have been found to live in the areas near
      black smokers. Additional information is available from [a
      HREF="http:]/www.nhm.ac.uk/science/mineral/project5/">The
      Natural History Museum of London and [a
      HREF="http:]/www.amnhonline.org/expeditions/blacksmokers/">The
      American Museum of Natural History Expeditions.