The Collaborative International Dictionary of English v.0.48:

marten \mar"ten\, n. [From older martern, marter, martre, F.
   martre, marte, LL. martures (pl.), fr. L. martes; akin to AS.
   mear[eth], meard, G. marder, OHG. mardar, Icel. m["o]r[eth]r.
   Cf. Foumart.]
   1. (Zool.) Any one of several fur-bearing carnivores of the
      genus Martes (formerly Mustela), closely allied to the
      sable. Among the more important species are the European
      beech marten or stone marten (Martes foina); the
      pine marten (Martes martes); and the American
      marten, or sable (Martes Americana), which some
      Zoologists consider only a variety of the Russian sable.
      [1913 Webster +PJC]

   2. The fur of the marten, used for hats, muffs, etc.
      [1913 Webster]

WordNet (r) 3.0 (2006):

Martes foina
    n 1: Eurasian marten having a brown coat with pale breast and
         throat [syn: stone marten, beech marten, Martes
         foina]