Source : Webster's Revised Unabridged Dictionary (1913)

Lupus \Lu"pus\, n. [L., a wolf. See {Wolf}.]
   1. (Med.) A cutaneous disease occurring under two distinct
      forms.

   Note: Lupus erythematosus is characterized by an eruption of
         red patches, which become incrusted, leaving
         superficial scars. L. vulgaris is marked by the
         development of nodules which often ulcerate deeply and
         produce great deformity. Formerly the latter was often
         confounded with cancer, and some varieties of cancer
         were included under Lupus.

Source : WordNet®

lupus
     n 1: any of several forms of ulcerative skin disease
     2: a constellation in the southern hemisphere near Centaurus