The Collaborative International Dictionary of English v.0.48:

Hypochondriac \Hy`po*chon"dri*ac\, a. [Gr. ? affocated in the
   hypochondrium: cf. F. hypocondriaque, formerly spelt
   hypochondriaque.]
   1. Of or pertaining to hypochondria, or the hypochondriac
      regions.
      [1913 Webster]

   2. Affected, characterized, or produced, by hypochondriasis.
      [1913 Webster]

   Hypochondriac region (Anat.), a region on either side of
      the abdomen beneath the cartilages of the false ribs,
      beside the epigastric, and above the lumbar, region.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Hypochondriac \Hy`po*chon"dri*ac\, n.
   A person affected with hypochondria.
   [1913 Webster]

         He had become an incurable hypochondriac. --Macaulay.
   [1913 Webster]

WordNet (r) 3.0 (2006):

hypochondriac
    adj 1: suffering from hypochondria [syn: hypochondriac,
           hypochondriacal]
    n 1: a patient with imaginary symptoms and ailments