Source : Webster's Revised Unabridged Dictionary (1913)

Meerschaum \Meer"schaum\, n. [G., lit., sea foam; meer sea +
   schaum foam; but it perh. is a corruption of the Tartaric
   name myrsen. Cf. {Mere} a lake, and {Scum}.]
   1. (Min.) A fine white claylike mineral, soft, and light
      enough when in dry masses to float in water. It is a
      hydrous silicate of magnesia, and is obtained chiefly in
      Asia Minor. It is manufacturd into tobacco pipes, cigar
      holders, etc. Also called {sepiolite}.

   2. A tobacco pipe made of this mineral.

Source : WordNet®

meerschaum
     n 1: a white clayey mineral [syn: {sepiolite}]
     2: a pipe having a bowl made of meerschaum