The Collaborative International Dictionary of English v.0.48:

Lupus \Lu"pus\, n. [L., a wolf. See Wolf.]
   1. (Med.) originally, a cutaneous disease with the appearance
      of the skin having been gnawed, and occurring under two
      distinct forms. Now used as a generic term for over ten
      distinguishable diseases having visible cutaneous
      symptoms.
      [1913 Webster +PJC]

   Note: Lupus erythematosus is characterized by an eruption
         of red patches, which become incrusted, leaving
         superficial scars. Lupus vulgaris is marked by the
         development of nodules which often ulcerate deeply and
         produce great deformity. Prior to 1900 the latter was
         often confounded with cancer, and some varieties of
         cancer were included under Lupus. Systemic lupus
         erythematosus is an inflammatory connective tissue
         disease occurring mostly in women, characterized by
         skin rash, fever, and arthritic symptoms, and often
         accompanied by hemolytic anemia, inflammation of the
         pericardium, glomerular lesions, and hyperglobulinemia;
         the condition shows positive in the LE cell test.
         --[Stedman]br/ [1913 Webster +PJC]

   2. (Astron.) The Wolf, a constellation situated south of
      Scorpio.
      [1913 Webster]

WordNet (r) 3.0 (2006):

lupus erythematosus
    n 1: a chronic inflammatory collagen disease affecting
         connective tissue (skin or joints) [syn: lupus
         erythematosus, LE]