The Collaborative International Dictionary of English v.0.48:

marasmus \ma*ras"mus\, n. [NL., fr. Gr. ?, fr. ?, to quench, as
   fire; pass., to die away.] (Med.)
   A wasting of flesh without fever or apparent disease; a kind
   of consumption; atrophy; phthisis.
   [1913 Webster]

         Pining atrophy,
         Marasmus, and wide-wasting pestilence.   --Milton.
   [1913 Webster]

   Marasmus senilis [L.], progressive atrophy of the aged.
      [1913 Webster] Marathi

WordNet (r) 3.0 (2006):

marasmus
    n 1: extreme malnutrition and emaciation (especially in
         children); can result from inadequate intake of food or
         from malabsorption or metabolic disorders