The Collaborative International Dictionary of English v.0.48:

Macula \Mac"u*la\, n.; pl. Maculae. [L., spot, stain, blot.
   See Mail armor, and cf. Mackle, Macule.]
   1. A spot, as on the skin, or on the surface of the sun or of
      some other luminous orb; called also macule.
      [1913 Webster]

   2. (Zool.) A rather large spot or blotch of color.
      [1913 Webster] macula lutea

WordNet (r) 3.0 (2006):

macula
    n 1: a cooler darker spot appearing periodically on the sun's
         photosphere; associated with a strong magnetic field [syn:
         sunspot, macula]
    2: a small yellowish central area of the retina that is rich in
       cones and that mediates clear detailed vision [syn: macula,
       macula lutea, macular area, yellow spot]
    3: a patch of skin that is discolored but not usually elevated;
       caused by various diseases [syn: macule, macula]